A Universal 通用 Double-Side 双侧 Passivation 钝化 for High 高开 Open-Circuit

Transcription

1 Full paper 太阳能电池 Solar Cells A Universal 通用 Double-Side 双侧 Passivation 钝化 for High 高开 Open-Circuit Voltage in 钙钛矿 Perovskite 太阳能电池 Solar Cells: 作用 Role of 羰基 Carbonyl Groups 基 in 聚 Poly(methyl 甲基 methacrylate) Jun Peng, Jafar I. Khan, Wenzhu Liu, Esma Ugur, The Duong, Yiliang Wu, Heping Shen, Kai Wang, Hoang Dang, Erkan Aydin, Xinbo Yang, Yimao Wan, Klaus J. Weber, Kylie R. Catchpole, Frédéric Laquai, Stefaan De Wolf,* and 和 Thomas P. White* photovoltaics (PV). [1 6] Ever since 以来 the 开创 pioneering 工作 work by Miyasaka reporting the The performance 性能 of state-of-the-art 最先进钙钛矿 perovskite 太阳能电池 solar cells is 目前 currently 限 limited by defect-induced 缺陷诱导 recombination 复合 at interfaces 界面 between the 钙钛矿 perovskite first 第一钙钛矿 perovskite 太阳能 solar 电池 cells with 功率 power conversion 转换效率和 and the 电子 electron 和 and 空穴 hole 传输 transport 层 layers. 这些 These 缺陷 defects, most 很可能 likely efficiencies (PCE) of 3.8% in 2009, [7] 大 much of the 研究 research 工作 effort has 不协调 undercoordinated Pb 和 and halide 离子 ions, must 必须 either be 除去 removed 或 or 钝化 passivated if been 集中 focused on 控制 controlling the 钙钛矿 perovskite 电池效率 cell efficiencies are to 接近 approach 其 their 理论 theoretical 极限 limit. In 这项 this 工作 work, a 通用 universal composition 组成和 and morphology, 形态 [8 12] 和 and 双 double-side polymer 聚合物 passivation 钝化 approach 方法 is introduced 引入 using ultrathin 超薄 engineering 工程专用 dedicated 空穴 hole- 和 and 电子 electron 聚 poly(methyl 甲基 methacrylate) (PMMA) 薄膜 films. 非常 Very 高 high-efficiency 高效 ( 20.8%) transport 传输层 layers (HTLs 和 and ETLs). [13 16] 钙钛矿 perovskite 电池 cells with some 一些 of the 最高 highest 开 open circuit 电压 voltages (1.22 V) 综合 Combined improvements 改进 in 每个 each of these 个领域 areas have led to the 目前 current PCE 记录 record 报告 reported for the same 相同 1.6 ev bandgap 带隙 are demonstrated. 展示 Photoluminescence 光致发光 of >22%. [17] 钙钛矿 Perovskite 太阳能电池 solar cell 稳定性 stability 成像 imaging 和 and 瞬态 transient 光谱 spectroscopic 测量 measurements 证实 confirm a significant is 也 also 增加 increasing, with 报道 reports of 电池 cells 减少 reduction in 非辐射 nonradiative 重组 recombination in the 钝化 passivated 细胞 cells, consistent 一致 maintaining 保持 high-efficiency 高效率 (>20%) under with the 电压 voltage increase. 增加分析 Analysis of the molecular 分子 interactions 相互作用 between prolonged 长时间 ( 1000 hours) 小时 one-sun 太阳照射 illumination 和 and at 增加 elevated 工作 operating 温度 tempera- 钙钛矿 perovskite 和 and PMMA reveals 表明 that the 羰基 carbonyl (C O) groups 基团 on the PMMA are 原因 responsible for the 优异 excellent 钝化 passivation via 路易斯 Lewis-base 碱电子 electronic tures (60 C). [18] 这种 This 快速 rapid 进步 progress is encouraging for the future commercialization of 钙钛矿 perovskite PV 技术 technology. passivation of Pb 2+ 令人鼓舞未来商业化钝化 ions. 离子这项 This work 工作 provides 提供 new 新 insights 见解 and 和 a 令人信服 compelling explanation 解释 of how PMMA passivation 钝化 works, 工作 and 和 suggests 提出 future 未来 directions 方向 To 迄今 date, the best-performing 最佳 cells 电池使用 use for developing 开发 improved 改进 passivation 钝化层 layers. 活性 active layers 层 consisting of a 混合 mixed 卤化物 halide 和 and 混合 mixed 阳离子 cation 钙钛矿 perovskite 组成 composition with a 带隙 bandgap (E g ) of 1.6 ev. The 1. Introduction 理论 theoretical (Shockley Queisser) PCE limit 限 for this 该带隙 bandgap is >30%; well above the 目前 current 实验 experimental 记录 record. [19,20] A 钙钛矿 Perovskite solar 太阳能 cells 电池 combine 结合 a 高 high 吸收 absorption 系数 coefficient number of recent 最近 studies 研究 have 有 identified 发现非辐射 nonradiative 载流子 carrier with 长 long 载流子 carrier diffusion 扩散长度 lengths, which are 重要 important recombination 重组 via 缺陷 defects (traps) 陷阱 at the 钙钛矿 perovskite-transport 传输因素 factors 解释 explaining 它们 their 快速 rapid 上升 rise to the 前沿 forefront of 薄 thin-film 薄膜 layer 层 interfaces 界面 as a major 主要来源 source of 效率 efficiency 损失 loss in state-ofthe-art 细胞 cells. [19] 虽然 Although the 确切 exact nature 性质 of these 这些 is 仍 still to be confirmed, 证实 both 理论 theoretical 和 and 实验 experimental 证据 evidence points to undercoordinated Pb (Pb 2+ ) 和 and/or 或卤化物 halide (I ) 离子 ions as the J. Peng, Dr. T. Duong, Y. Wu, Dr. H. Shen, Dr. Y. Wan, Dr. K. J. Weber, Prof. K. R. Catchpole, Dr. T. P. 白色 White dominant 主要复合 recombination-active 活性 defects 缺陷 at interfaces 界面 of asdeposited 薄膜 films, at grain 界 boundaries, 和 and 也 also in the 批量 bulk. [21 25] 研究 Research 院 School of 工程 Engineering The Australian 澳大利亚 National 国大学 University On a 器件 device level, 级非辐射 nonradiative 复合 recombination via these 这些 defects 缺陷 Canberra, ACT 2601, Australia 澳大利亚 reduces 降低 the 开 open circuit 电压 voltage (V oc ) 和 and 整体 overall 器件 device performance. 接口 Interface 缺陷 defects have 有 also 也 been 有关 linked to 滞后 hysteresis 性能 邮件托马斯 thomas.white@anu.edu.au Dr. J. I. Khan, Dr. W. Liu, E. Ugur, Dr. K. Wang, Dr. H. Dang, Dr. E. Aydin, in 电流 current voltage 电压特性 characteristics, [26,27] 与 and 可能 may 也 also 影响 impact Dr. X. Yang, Dr. F. Laquai, Dr. S. De Wolf 王 King Abdullah University 大学 of Science 科学 and 与 Technology (KAUST) 长期 long-term 期稳定性 stability. [28] To 弥合 bridge the 差距 gap between the 辐射 radiative KAUST Solar 太阳能中心 Center (KSC) efficiency 效率 limit 极限和 and 实验 experimental PCE 值 values, 其 it is 因此 therefore 物理 Physical Sciences 科学 and 与工程 Engineering Division (PSE) imperative 必须 to minimize the 来源 sources of 复合 recombination in 钙钛矿 perovskite 薄膜 films 和 and 其 their 界面 interfaces. [19,20] stefaan.dewolf@kaust.edu.sa Thuwal , Kingdom of Saudi 沙特阿拉伯 Arabia 几 Several 最近 recent 研究 studies 表明 suggest that 界面 interface 钝化 passivation The ORCID identification number(s) for the 作者 author(s) of 本 this 本文 article can 可以 significantly 减轻 mitigate 非辐射 nonradiative 复合 recombination in 细胞 cells, 可以 can be found 找到 under yielding 产生 both improved 改善 V oc 和 and 器件 device 稳定性 stability. [29 38] 许多 Many of DOI: /aenm these 这些钝化 passivation 方案 schemes 针对 target the 正 positively 电荷 charged Pb (1 of 9)

2 Figure 1. 示意图 Schematic of the device 器件 structure 结构和 and 相应 corresponding SEM 横 cross-sectional 横截面图像 image. a) 示意图 Schematic of the 器件 device 结构 structure. b) SEM cross-sectional 横横截面 image 图像 of the 钙钛矿 perovskite cell. 电池 Note 注意 that the Pt protection 保护 layer 层 seen 见 in (b) was only 仅 used 用 to prepare 制备 the focused 聚焦 ion 离子束 beam (FIB) SEM cross-sectional 横横截面 image. 图像 Perovskite 钙钛矿 refers 指 here 这里 to the composition Cs 0.07 Rb 0.03 FA MA PbI 2.55 Br defect 缺陷 using 电子 electron 供体 donor 材料 materials, 或 or Lewis-bases. 碱 This 这种 general 电子 electron-passivation 钝化方法 approach was 首次发现 first identified by Noel 通用 et al., in ref. [21] where perovskite 钙钛矿薄膜 films 和 and 电池 cells 处理 treated with the 路易斯 Lewis bases 碱 thiophene 噻吩和 and 吡啶 pyridine were 显示 shown to 显示 display significantly increased 增加载流子 carrier 寿命 lifetimes 和 and 开 open-circuit 电压 voltages. Since 那时起 then, various 各种 other 其他路易斯 Lewis-base 碱 passivation 钝化 materials 材料 have 已 been 已经确定 identified, 包括 including the 聚合物 polymers 聚 poly(4-vinylpyridine) (PVP), [29] 和 and PCDTBT, [30] which 可以 can be 用 applied either as an 超薄 ultrathin 界面 interface 层 layer 或 or 混合 blended with the 钙钛矿 perovskite 前体 precursor 溶液 solution. Other 其他有机 organic 钝化 passivation materials 材料包括 include 富勒烯 fullerenes and their 其衍生物 derivatives (e.g., C60, [31] 苯基 phenyl-c61-butyric 丁酸 acid 酸甲基 methyl 酯 ester (PCBM) [32 34] ), graphene, 石墨烯 [35] and 和聚 poly(methyl 甲基 methacrylate) (PMMA). [36 38] PCBM has been 报道 reported to passivate 不协调 undercoordinated I atoms 原子 (I ) at the 表面 surface 和 and grain 界 boundaries of perovskite 钙钛矿 films, 薄膜 [34] but 但 the 钝化 passivation mechanism 机理 of PMMA is 不 not well understood. 清楚 PMMA has been shown by a number 许多 of 团体 groups to 有效 effectively reduce 降低 trap 陷阱 density 密度并 and 改善 improve 电池 cell 性能 performance when inserted 插入 as an 超薄 ultrathin 层 layer either before 或 or after the 钙钛矿 perovskite 薄膜 film 沉积 deposition. [36 38] 这 This has been 不同 variously attributed 归因 to improved 改进 perovskite 钙钛矿 microstructure 微观结构 and 和表面 surface 形态 morphology, [36,37] 填充 filling of pinholes, 和 and 未指定 unspecified passivation 钝化 of 表面 surface traps. 陷阱 [38] PMMA has 也 also been used 用 as an 添加剂 additive during 钙钛矿 perovskite 薄膜 film 沉积 deposition to 控制 control 晶体 crystal 生长 growth 和 and 形态 morphology, but 但 its 它的钝化 passivation properties 特性 in 这种 this 情况 case were 没有被明确 not explicitly considered. 考虑 [36,37] Here, 这里 we 我们制造 fabricate 双 double-side 钝化 passivated 钙钛矿 perovskite 电池 cells by inserting 插入超薄 ultrathin PMMA 薄膜 films at both the 钙钛矿 perovskite/etl and 和钙钛矿 perovskite/htl 界面 interfaces. 这种 This 对称 symmetric passivatingcontact 结构 structure significantly 减少 reduces 界面 interface 复合 recombination, as 证明 evidenced by 改善 improved 工作 operating 电压 voltages, and 和 corroborated 证实 by 光致发光 photoluminescence (PL) 成像 imaging, 时间 time-resolved 分辨光致发光 photoluminescence (TRPL), and 和 transient 瞬态吸收 absorption (TA) 测量 measurements. 双 Double-side 钝化 passivated 电池 cells have been 制造 fabricated with an 效率 efficiency of 20.8% 并 and a remarkable V oc of 1.22 V with 可忽略 negligible 滞后 hysteresis. 这 This yields 一 one of the 最低 lowest E g qv oc 值 values reported 报告 to 迄今 date (q is the 基本 elementary 电荷 charge). [39 41] The passivation 钝化 mechanism 机制 is 研究 investigated using a 组合 combination of 傅里叶 Fourier-transform 变换 infrared 红外 (FTIR) and 和核 nuclear 磁 magnetic resonance 共振 (NMR) 光谱 spectroscopy measurements, 测量 supported 支持 by density 密度泛函 functional 理论 theory (DFT) 计算 calculations. 我们 We 发现 find strong evidence 证据 that the 优异 excellent 钝化 passivation 提供 provided by the PMMA films 薄膜 is 有关 associated with the 路易斯 Lewis-base 碱性质 nature of the 氧 oxygen atoms 原子 in the 羰基 carbonyl (C O) 基团 groups of PMMA. 我们 We 因此 thus 得出结论 conclude that PMMA is 类似 similar to 其他 other 路易斯 Lewis-base 基 polymer 聚合物 passivation 层 layers, where donor 供体 electrons 电子可以 can 减少 reduce the charge 电荷 state 状态钝化 of Pb 2+ 缺陷 defect 离子 ions at the 钙钛矿 perovskite/etl 和 and 钙钛矿 perovskite/htl 界面 interfaces, 有效 effectively reducing 减少非辐射 nonradiative 复合 recombination. 这项 This 工作 work not 不不仅 only demonstrates 展示 a 通用 universal, simple 简单 and 和有效 effective interface 界面 passivation 钝化 treatment 处理 to 提高 boost the 性能 performance of state-of-the-art 最先进钙钛矿 perovskite solar 太阳能电池 cells, but 而 also 而且提供 provides 新 new 物理 physical insights 见解 into passivation 钝化 mechanisms 机制 that 可以 could lead to further 进一步 improvements in 器件 device 性能 performance. 2. Results 结果 and 和 Discussion 讨论 To 实现 realize a 钙钛矿 perovskite 太阳能 solar 电池 cell with 高 high 工作 operating 电压 voltage and 和可忽略 negligible 滞后 hysteresis, we 我们引入 introduce interface 界面 passivation 钝化 on both the ETL 和 and HTL 侧 sides in 多 multi-cation 阳离子钙钛矿 perovskite 电池 cells. Our 我们的器件 device structure 结构 is FTO/c-In-TiO x /m-tio 2 /PMMA:PCBM/ 钙钛矿 perovskite/pmma/spiro-ometad/au (see 见图 Figure 1a,b), where the c-in-tio x, [42] m-tio 2, Perovskite 钙钛矿 and 和 Spiro-OMeTAD represent compact 铟 indium-doped 掺杂 TiO x, mesoporous 介孔 TiO 2, Cs 0.07 Rb 代表 0.03FA MA PbI 2.55 Br 0.45, and (2,2,7,7 -tetrakis-(n,n-di-4- 四二 methoxyphenylamino)-9,9 -spiro-bifluorene), 螺 respectively. The thickness 厚度 of 每 each 层 layer is shown 显示 in the 横 cross-sectional 横截面 scanning 扫描 electron 电子显微镜 microscope (SEM) 图像 image in Figure 图 1b. 我们 We use 使用 the perovskite 钙钛矿 solar 太阳能电池 cell 没 devoid of 任何 any 钝化 passivation 层 layer as a 控制 control 装置 device, where the architecture 结构 is FTO/c-In-TiO x /m-tio 2 / 钙钛矿 Perovskite/Spiro-OMeTAD/Au. As seen in 图 Figure 2a, the 控制 control device 装置 yielded a PCE of 19.5% from a 反向 reverse 电流 current voltage 电压扫描 scan, with V oc = V, 短 short-circuit current 电流密度 density J sc = ma/cm 2 和 and 填充因子 fill-factor FF = A small 少 amount 量 of 滞后 hysteresis is 还 also 观察到 observed, with a 正向 forward 扫描 scan 产生 yielding PCE = 18.5%. Details 详细信息 of the 扫描 scan 速率 rate 和 and J V 测量 measurement 程序 procedure are 提供 provided in the 支持 Supporting 信息 Information. After 插入 inserting an 超薄 ultrathin PMMA:PCBM (2 of 9)

3 Figure 2. Device 设备 performance 性能和 and PL 成像 imaging. a,b) 正向 Forward- and 和反向 reverse-scan 扫描 J V curves 曲线 of the 控制 control 单元 cell with a 结构 structure of FTO/c-In-TiO x /m-tio 2 / 钙钛矿 Perovskite/Spiro-OMeTAD/Au, and 和 its 其 corresponding 相应 photoluminescence 光致发光 (PL) 图像 image. c,d) J V 曲线 curves of the 钝化 passivated ETL side 侧 cell 电池 with a structure 结构 of FTO/c-In-TiO x /m-tio 2 /PMMA:PCBM/Perovskite/Spiro-OMeTAD/Au, 钙钛矿 and its 其 corresponding 相应 PL image. 图像 e) and 和 f) J V 曲线 curves of the 双 double-side 钝化 passivated 电池 cell with a 结构 structure of FTO/c-In-TiO x /m-tio 2 /PMMA:PCBM/Perovskite/PMMA/Spiro-OMeTAD/Au, 钙钛矿 and 和其 its 相应 corresponding PL 图片 image. Perovskite 钙钛矿 refers 指 to the composition 组成 Cs 0.07 Rb 0.03 FA MA PbI 2.55 Br 钝化 passivation layer 层 at the m-tio 2 /perovskite 钙钛矿界面 interface (labeled 标记 as of the 双 double-side 侧 passivated 钝化 cells 细胞 is much 多 shorter than that of passivated 钝化 ETL 侧 side), the V oc 增加 increased to V, yielding a the 对照 control 细胞 cells, taking less 小 than 3 s to 达到 reach 其 their 稳态 steady-state 态 PCE of 20.3% (see 见图 Figure 2c), which is consistent 一致 with 我们 our 值 value after exposure to 光照 light (see 见 Figure 图 S1 in the 支持 Supporting previous 以前工作 work. [43] 启发 Inspired by 此 this 发现 finding, 我们还 we also 插入 inserted an 信息 Information). ultrathin 超薄纯 pure PMMA 薄膜 film (details 详细信息 in the 支持 Supporting 信息 Information) at the HTL/perovskite 钙钛矿界面 interface. Encouragingly, this 这种 state 效率 efficiency and 和外 external 量子 quantum 效率 efficiency (EQE) 测量 meas- 器件 Device performance 性能 was 进一步 further 表征 characterized with steady- double-side 双钝化 passivation significantly boosted the V oc to V, urements. 图 Figure S2 (Supporting 支持 Information) 信息显示 shows the 产生 resulting in a 冠军 champion 细胞 cell with a PCE of 20.8% and 可忽略不计 negligible 滞后 hysteresis as seen in Figure 图 2e. Consistent 一致 with the 其 its V mpp (maximum 最大功率 power 点 point 电压 voltage) of 0.93 V for 600 s. 稳态 steady-state 态 PCE of the 对照 control 电池 cell to be 18.7%, 测试 tested at reduced 滞后 hysteresis, 我们还 we also 发现 find that the 瞬态 transient V oc 响应 response 值得注意 Notably, the 稳态 steady-state 态 PCE of the 钝化 passivated 细胞 cells was much (3 of 9)

4 Figure 3. Statistical 统计 distribution 分布 of the 光伏 photovoltaic 参数 parameters for 对照 control 和 and 钝化 passivated 电池 cells with/without PMMA:PCBM 和 and PMMA passivation 钝化 layer. 层 a) Distribution of V oc. b) Distribution of J sc. c) Distribution of FF. d) Distribution of PCE. Note 注意 that control 对照 represents 代表 the 对照 control 细胞 cells with a 结构 structure of FTO/c-In-TiO x /m-tio 2 /Perovskite/Spiro-OMeTAD/Au; 钙钛矿 P-1 side 侧 represents 代表 the 钝化 passivated ETL side 侧 cells 细胞 with a 结构 structure of FTO/c-In- TiO x /m-tio 2 /PMMA:PCBM/Perovskite/Spiro-OMeTAD/Au; 钙钛矿 the P-2 side 侧 represents 代表 the 双 double-side 侧钝化 passivated 细胞 cells with a 结构 structure of FTO/c-In- TiO x /m-tio 2 /PMMA:PCBM/Perovskite/PMMA/Spiro-OMeTAD/Au. 钙钛矿 Perovskite 钙钛矿 represents 代表 Cs 0.07 Rb 0.03 FA MA PbI 2.55 Br 结果 Results are 显示 shown for 60 cells 细胞 (20 cells 细胞 for each 每种 condition) 条件收集 collected from 2 不同 different batches. 批次所有器件 All devices were tested 测试 at a 50 mv s 1 反向 reverse scan 扫描速率 rate. improved 改进 with respect to the 控制 control 装置 device, resulting in a stabilized PCE of 20.1% (tested at V mpp = 0.97 V) and 20.7% (tested at V mpp = 1.0 V) for the ETL-side 侧 passivated 钝化 cell 细胞 and 和 the 双 double-side 侧钝化 passivated 细胞 cells, 分别 respectively. 我们 We 还 also 进行 performed a 更 much 更长 longer ( 10 h) 稳态 steady-state 态效率 efficiency 测量 measurement 参见 (see 图 Figure S2d in the 支持 Supporting 信息 Information), which showed 表明 that the PMMA passivation 钝化 treatment 处理有效 effectively improves 改善 the lightsoaking stability 稳定性 of cells. 细胞 EQE measurements 测量 on the 对照 control 和 and 钝化 passivated 电池 cells 显示 show 没有 no significant 变化 variation with the 添加 addition of the 钝化 passivation 层 layers (Figure 图 S3, Supporting 支持信息 Information) and 和 the integrated 当前 current from EQE 光谱 spectra are within 3% of the 值 values 获得 obtained from current voltage 当前电压 measurements. 测量 In order to quantify 量化 more 更 accurately 准确 the impact 影响 of the passivation layers, 层 we 我们制造 fabricated and 并 measured 测量 twenty 电池 cells for 钝化每种 each 条件 condition (control, 控制 ETL-side 侧钝化 passivation, double-side 双侧 passivation) in 两个 two separate 批次 batches. 图 Figure 3 显示 shows the 详细 detailed 钝化分布 distribution of the 性能 performance 参数 parameters 提取 extracted from 反向 reverse-scan 扫描 measurements. 测量 It is 明显 clear that the 最 most 重要 significant 影响 impact of the 钝化 passivation is to increase 增加 the V oc. The 平均 average V oc of the 对照 control 细胞 cells is 1.10 ± 0.01 V. 这 This 增加 increases to 1.16 ± 0.01 V with ETL-side 侧钝化 passivation, and 和 1.20 ± 0.01 V for the 双 double-side 侧钝化 passivated 电池 cells, respectively 分别 corresponding 对应 to a 相对 relative increase 增加 of 5.4% and 9.1% compared 相比 to that of 对照 control 细胞 cells. At the 同 same 时 time, the FF and 和 J sc for the 双 double-side passivated 钝化 cells 电池 are both reduced 略有 slightly (by 2.4% and 0.5% relative, 相对 respectively), which we 我们归因 attribute to a small 小 reduction 下降 in the 载波 carrier-extraction 提取效率 efficiency and 和增加 increased series 电阻 resistance 产生 resulting from the 绝缘 insulating PMMA 薄膜 film. 然而 Nevertheless, the 小 small penalty in 这些 these 参数 parameters is more than 补偿 compensated by the 增加 increased voltage. 电压 As a 结果 result, the average 平均电池 cell 效率 efficiency 增加 increases from 18.8 ± 0.5% for the 对照 control 细胞 cells to 19.9 ± 0.5% for the 双 double-side 侧钝化 passivated 细胞 cells. 我们 We 还 also note 注意 that the 最好 best 双 double-side 侧 passivated 钝化 cell 电池 yielded 产生 a remarkable V oc = 1.22 V (see 参见 also 图 Figure S4 in the 支持 Supporting 信息 Information), which is amongst the 最高 highest 报告 reported 值 values for 1.6 ev 带隙 bandgap 钙钛矿 perovskite. [39 41] To 验证 verify that the improved 改善 device 器件 performance 性能 is a result 结果 of interface 界面钝化 passivation, and 和 not 不 due to a change 变化 in bulk 体积 properties 性质 or 或膜 film 形态 morphology 我们研究 we investigated the 沉积 deposited 膜 films using X-ray 射线衍射 diffraction (XRD) and 和 SEM. XRD spectra 光谱 reveal 显示 no 没有系统 systematic 变化 variations due to the 钝化 passivation 处理 treatment. 没有明显 No obvious PbI 2 或 or 其他 other nonperovskite 相 phases are 观察到 observed; nor is there a significant 变化 variation in 微晶 crystallite 尺寸 size, as shown in 图 Figure S5 (Supporting 支持信息 Information). From SEM 检查 inspection there is 没有 no significant 差异 difference in the 顶部形态 top-morphology of 钙钛矿 perovskite 薄膜 films in 对照 control 和 and 钝化 passivated 钙钛矿 perovskite (see 参见图 Figure S6 in the 支持 Supporting 信息 Information). Subsequently, 随后我们 we 进行 performed PL imaging 成像 on the 对照 control 和 and 钝化 passivated 细胞 cells under 开 open-circuit 条件 conditions (see 参见 Figures 图 2b,d,f). The PL intensity 强度 of the 最好 best ETL-side 侧钝化 passivated perovskite 钙钛矿 cell 细胞 and 和双 double-side 侧 passivated 钝化 cell 细胞 increased 增加 more than 5-fold 和 and 34-fold, respectively 分别 compared 相比 to the 对照 control cell. 细胞 From 此 this, it 此 is evident that the nonradiative 非辐射 recombination 复合 was significantly 降低 reduced by the PMMA:PCBM 和 and PMMA (4 of 9)

5 Figure 4. 光致发光 Photoluminescence 动力学 dynamics from 时间 time-resolved 分辨 (TR-PL) measurements. 测量 a) ETL 仅 only samples 样品 (illuminated 照射 from the ETL side): 侧钙钛矿 perovskite, ETL/perovskite, 钙钛矿 ETL/PMMA:PCBM/Perovskite 钙钛矿 and 和 ETL/PMMA:PCBM/Perovskite/PMMA. 钙钛矿 b) HTL 仅 only 样品 samples (illuminated 照射 from the HTL 侧 side): 钙钛矿 perovskite, perovskite/htl 钙钛矿 and 和 perovskite/pmma/htl. 钙钛矿 Note 注意 that all 所有样品 samples were fabricated 制造 on high-grade 高级 optical 光学 quartz 石英基板 substrates. ETL, HTL, and 和钙钛矿 perovskite 代表 represent c-in-tio x /m-tio 2, Spiro-OMeTAD, and 和 Cs 0.07 Rb 0.03 FA MA PbI 2.55 Br 0.45, respectively. passivation. 减少 Reduced nonradiative 非辐射 recombination 复合增加 increases the 过量 excess charge 电荷 carrier 载流子 density 密度 in the active 层 layer under steadystate 开 open circuit 条件 conditions, increasing 增加 the quasi 准费米 Fermi 能级 level 分裂 splitting and 并 thus 因此增加 increasing the V oc of the 电池 cells. [44] 这 This further 进一步证实 confirms the 起源 origin of the 改进 improved V oc in the passivated 钝化钙钛矿 perovskite cells. 细胞 The PL 图像 images 也 also 显示 show 良好 good 钝化 passivation 均匀性 uniformity over the 整个 whole 器件 device area. 区域 A reduction 降低 in 复合 recombination rate 率 with the 引入 introduction of the PMMA 层 layers is 也 also 观察到 observed in 时间 time-resolved 分辨 PL 测量 measurements shown in Figure 图 4. 两 Two 组 sets of 样品 samples were 制备 prepared to 研究 investigate 分别 separately the 影响 impact of 钝化 passivating the ETL and 和 HTL interfaces. 界面时间 Time-resolved 分辨 PL spectra 光谱 were measured from the 相关 relevant 传输 transport layer 层 side 侧 using a 650 nm 测量波长 wavelength pulsed 脉冲 laser 激光 as the 激发 excitation 源 source. The 光谱 spectral 演变 evolution is 显示 shown in Figure 图 S7 (Supporting 支持信息 Information); the 钙钛矿 perovskite layer 层 shows 显示 the 特征 characteristic PL peak 峰 at 770 nm without 任何 any 额外 additional 光谱 spectral 特征 feature. 图 Figure 4a 显示 shows PL 瞬变 transients measured 测量 at the 峰值 peak 发射 emission 波长 wavelength for 代表性 representative samples 样品 with and 和 without a 钝化 passivation 层 layer between the 钙钛矿 perovskite and 和 the ETL (no 没有 HTL was included 包括 in 这些 these 样品 samples). To 测量 measure the 影响 impact of the 提取 extraction 层 layer 和 and 影响 effect of passivation 钝化 on the PL 动力学 dynamics, the PL transients were 拟合 fitted with a 和 sum of 两个 two 指数 exponential 函数 functions 和 and the 加权 weighted-average 平均 lifetimes 寿命 were 计算 calculated. 我们 We 注意 note that 这 this is 仅仅 merely a 参数化 parameterization of the PL 动力学 dynamics, which 缺乏 lacks 物理 physical meaning. 意义 In 事实 fact, it has been shown 表明 that the photogenerated 少数 minority 载流子 carrier 寿命 lifetime of 钙钛矿 perovskites is 主要 dominated by 光生 a 组合 combination of 一 first, second, 和 and 三 third 阶 order 复合 recombination 过程 processes. 这些 These are 分别 respectively 相当 equivalent to 陷阱 trap-assisted 辅助非辐射 nonradiative (Shockley Read Hall), 带 band-to-band 带辐射 radiative (bimolecular, 双分子 two-particle), 粒子 and 和俄歇 Auger (three-particle) 三粒子重组 recombination, which 需要 requires 注量 fluence-dependent 依赖性实验 experiments to 分离 separate the 不同 different 过程 processes. [45 48] 然而 However, this 这 is beyond the 范围 scope of the 本 present 工作 work and 因此 thus a 参数化 parameterization of the decays 衰变 was chosen 选择 instead. Using this parametrization 参数化 of the transients, 我们发现 we find for the 参考 reference ETL/perovskite 钙钛矿样品 sample an 平均 average PL 寿命 lifetime of 125 ns, while 而 the one-side 侧和 and twoside 钝化 passivated 样品 samples exhibit longer 平均 average PL 寿命 lifetimes of 195 和 and 245 ns, 分别 respectively. As 参考 reference, we 我们还 also measured 测量 the 原始 pristine 钙钛矿 perovskite 样品 sample without 任何 any 钝化 passivation 或 or interface 界面 to a 电荷 charge 提取 extraction layer 层 and 并发现 found a PL 寿命 lifetime of 738 ns. The PL 平均 average 寿命 lifetime 猝灭 quenching 观察到 observed upon addition 加入 of the ETL is attributed 归因 to a 组合 combined 效应 effect of 载体 carrier 提取 extraction (by the ETL) 和 and interface 界面 recombination. 重组 [25,49] The significant 寿命 lifetime 恢复 recovery 观察到 observed with the 添加 addition of the 超薄 ultrathin PMMA 钝化 passivation 层 layer 表明 indicates reduced 减少界面 interface recombination 重组 and 和有效 efficient 钝化 passivation of 陷阱 trap 状态 states 和 and recombination 重组中心 centers. Figure 图 4b 显示 shows PL 瞬变 transients for 钙钛矿 perovskite/htl 样品 samples with 和 and without the PMMA 钝化 passivation 层 layer (without using ETL in this 该配置 configuration). 有趣 Interestingly, the 平均 average PL 寿命 lifetime is 比 comparably shorter than for the ETL/perovskite 钙钛矿样品 samples, specifically 特别是 27 ns for the 钙钛矿 perovskite/htl 样品 sample 比 compared to 125 ns for the ETL/perovskite 钙钛矿 and 和 738 ns for the neat 钙钛矿 perovskite 膜 film, 意味 implying 非常 very 快 fast 提取 extraction 和 and/or 或引入 introduction of significant 表面 surface 重组 recombination. 然而 However, 插入 inserting a PMMA passivation 钝化 layer 层 at the 钙钛矿 perovskite/htl interface 界面 results in a significant 增加 increase in the PL 寿命 lifetime from 27 to 70 ns. Recombination 重组 dynamics 动力学 were also 还研究 investigated with transient 吸收 absorption (TA) spectroscopy 光谱 in the 纳米 nano-to-microsecond 微秒瞬态 time 时间窗口 window using a 532 nm 纳米脉冲 pulsed 激光 laser 激发 excitation 源 source (see 见 Supporting 支持信息 Information for details). 类似 Similar to the 瞬态 transient PL 测量 measurements, separate 单独 samples 样品 were prepared 制备 to 研究 study the ETL/perovskite 钙钛矿 and 和钙钛矿 perovskite/htl interfaces 界面 with 和 and without a 钝化 passivation 层 layer. TA measurements 测量 were 进行 performed with the pump 泵和 and 探测 probe 光 light 入射 incident from the 侧 side 最接近 closest to the 界面 interface of 感兴趣 interest. As with the PL 测量 measurements, 添加 adding charge 电荷提取 extraction layers 层 leads 导致 to faster 更快动态 dynamics 相比 compared to neat 纯钙钛矿 perovskite 薄膜 films, 而 while the 钝化 passivated 样品 samples 表现出 exhibited slower 更慢 decay 衰减动态 dynamics 相比 compared to the nonpassivated 样品 samples (see 参见图 Figure S8 in the 支持 Supporting 信息 Information). The 结果 results presented so 迄今为止 far 表明 show that 插入 inserting 超薄 ultrathin PMMA 薄膜 films at the ETL/perovskite 钙钛矿和 and HTL/perovskite 钙钛矿界面 interfaces can 可以 dramatically increase 提高 the 开 open-circuit 电压 voltage of our cells 电池 without significant 影响 impact on the 短 short-circuit 电流 current 或 or fill-factor. 填充因子这 This is 伴随 accompanied by both 增加 increased PL 强度 intensity and 和增加 increased 载流子 carrier 寿命 lifetime in the 钙钛矿 perovskite active 层 layer, indicating 表明 a 强烈 strong 减少 reduction in 非辐射 nonradiative 载流子 carrier 复合 recombination. 我们 We 因此 thus 得出结论 conclude that the PMMA 薄膜 films 可以 can 有效 effectively passivate interface 界面 traps/defects 陷阱缺陷 on both 侧 sides of the 钙钛矿 perovskite (5 of 9)

6 Figure 5. FTIR, NMR measurements, 测量 and 和 DFT calculation. 计算 a) FTIR spectra 光谱 of pure 纯 PMMA, PMMA + PbI 2, PMMA + PbI 2 + PbBr 2, and 和 PMMA + FAI thin 薄薄膜 film 样品 samples. b) 1H NMR 光谱 spectra of 纯 pure PMMA, PMMA + PbI 2 和 and PMMA + FAI. c) Schematic 示意图图 diagram of the 第一 first-principle 原理 DFT 计算 calculation of the 静电 electrostatic 势 potential for 所有官能 all functional groups 官能团 on the PMMA chain. 链 Details 详细信息 of the sample 样品 preparation 制备 are 提供 provided in the 支持 Supporting 信息 Information. active layer 层 while, 同时仍 still 允许 allowing 有效 efficient 载流子 carrier 提取 extraction into the 电荷 charge 传输 transport 层 layers. We 我们接下来研究 next investigate the 物理 physical 起源 origin of the 钝化 passivation 机制 mechanism and the 性质 nature of the 界面 interface 陷阱 traps/defects 缺陷 being 钝化 passivated. To do 此 this, we 我们使用 use Fourier 变换 transform 红外 infrared (FTIR) and 和核 nuclear 磁 magnetic 共振 resonance (NMR) 光谱 spectroscopy, combined 结合 with 数值 numerical 模拟 simulations to 识别 identify the 分子 molecular-level 水平 interactions 相互作用 at the 钙钛矿 perovskite PMMA interface. 界面 In a 以前 previous 研究 study of 聚合物 polymer-templated 模板钙钛矿 perovskite 薄膜 films, Bi et al. [36] 使用 used FTIR to 研究 study films 薄膜 of PMMA 和 and PMMA + PbI 2. The 光谱 spectral feature 特征相关 associated with the 伸缩 stretching 振动 vibration of the C O 共价 covalent bond 键 in the PMMA was 发现 found to 红 red-shift with the 添加 addition of the 路易斯 Lewis 酸 acid PbI 2. 这 This was attributed 归因 to the 形成 formation of an 中间 intermediate PMMA-PbI 2 加合物 adduct that influenced 影响膜 film 结晶 crystallization. In 相关 a related 研究 study, Masi et al. [37] 提出 proposed electrostatic 静电 interactions 相互作用 between the same 相同 C O (carbonyl) 羰基 group 基团 and 和正 positively 电荷 charged MA + 前体 precursor ions 离子 as playing a 关键 key 作用 role in 膜 film 形态 morphology. Here 这里我们首先 we first 使用 use FTIR to 探测 probe the 伸缩 stretching 振动 vibration of the C O bond 键 in 薄 thin 薄膜 films of 纯 pure PMMA, PMMA + PbI 2, PMMA + PbI 2 + PbBr 2, and 和 PMMA + 甲脒 formamidinium 碘化物 iodide (FAI). As can 可以 be 出现 seen in Figure 图 5a, the C O 光谱 spectral 特征 feature 相关 associated with 该 this 键 bond in 纯 pure PMMA 薄膜 film 出现 appears at 1732 cm 1, but 但 shifts 转移 to 1724 和 and 1725 cm 1 with the 添加 addition of PbI 2 和 and mixed 混合 PbI 2 + PbBr 2, respectively. 分别这 This 表明 indicates a 弱化 weakening of the C O 键 bond similar 类似 to the results 结果 of Bi et al. [36] 有趣 Interestingly, a larger 较大 spectral 光谱 shift (to 1720 cm 1 ) is measured 测量 for the PMMA + FAI 薄 thin 薄膜 film, which is 一致 consistent with the 静电 electrostatic 相互作用 interaction 提出 proposed by Masi et al., but 但涉及 involving FA + 离子 ions 而 rather than MA +. To 证实 confirm that the 主要 dominant 相互作用 interaction between PMMA and 和钙钛矿 perovskite is via the C O group 基团 (and 和 not 不一 one of the other 其他官能 functional 官能团 groups), we 我们还 also measured 测量 1H NMR 谱 spectra of PMMA, PMMA + PbI 2 和 and PMMA + FAI in DMSO-d6 solution. 图 Figure 5b shows 显示 that 过量 excess PbI 2 or 或 FAI does not 没有影响 affect the 溶液化学 chemical shift of 质子 protons on PMMA, indicating 表明 that there is no 没有 significant 相互作用 interaction between PbI 2 或 or FAI with the 饱和 saturated C 原子 atom 或 or H 原子 atom on the PMMA 链 chain. 因此 Thus, 我们有 we have 强有力 strong 证据 evidence that the PMMA carbonyl 羰基 group 基 can 可以 interact 相互作用 with multiple 钙钛矿 perovskite precursor 前体物质 species, the most 最 likely 可能 in this 这种情况 case 多种 being 正 positively charged 电荷 Pb 2+ 和 and FA + 离子 ions. The oxygen 氧原子 atom in a carbonyl 羰基 group 基 is a 路易斯 Lewis base 碱 (electron 供体 donor) 位点 site due to the 电子 electron 对 pair 相关 associated with the 电子 C O 双 double 键 bond. [50] 这 This is 清楚 clearly 观察到 observed as 局部 local 负 negative electrical 电 charge 电荷 (blue) 蓝色 surrounding 围绕 the 氧 oxygen atoms 原子 in Figure 图 5c, which plots 图 the 静电 electrostatic potential 势 of a PMMA chain 链计算 calculated using DFT). The 相互作用 interaction between 该 this local 局部 negative 负 charge 电荷 and 和 the Pb 2+ 和 and FA + 离子 ions 解释 explains the red-shift 红观察到 observed in the FTIR 光谱 spectra (Figure 图 5a). The 作用 role of Pb 2+ 缺陷 defects as 复合 recombination centers 中心 on the 表面 surface 和 and grain 界 boundaries of 固体 solid 钙钛矿 perovskite 薄膜 films is 被广泛 widely 接受 accepted, (6 of 9)

7 Figure 6. a) V oc and 和 PCE distribution 分布 of perovskite 钙钛矿 solar 太阳能电池 cells with different 不同 perovskite 钙钛矿 compositions. 组成 b) Hysteresis 滞后 index 指数 comparison 比较 of 钙钛矿 perovskite solar 太阳能 cells 电池 with and 和 without passivation. 钝化 Note 注意 that P-2 sides 侧 represents 表示双 double-side 侧 passivation; 钝化 and 所有器件 all devices were tested 测试 at a scan 扫描速率 rate of 50 mv s 1. The 滞后 hysteresis 指数 index is 定义 defined as: (PCE reverse PCE forward ) /PCE reverse. [51] 反向正向反向 as is the 能力 ability of 路易斯 Lewis 基础 base 材料 materials to passivate 这些 these 缺陷 defects. [21] 因此 Therefore 我们得出结论 we conclude that the 改进 improved 载流子 carrier 寿命 lifetime and 和 higher 更高光致发光 photoluminescence of films 薄膜和 and 电池 cells shown in 图 Figures 2 and 和 4 are a 直接 direct 结果 consequence of PMMA 钝化 passivating undercoordinated Pb 原子 atoms at the 钙钛矿 perovskite/etl 和 and 钙钛矿 perovskite/htl interfaces. 界面 This 这 leads 导致 to the outstanding 出色开 open circuit 电压 voltages and 和改善 improved 电池 cell 效率 efficiencies of 双 double-side 侧钝化 passivated cells 电池 demonstrated in 图 Figure 2. To 进一步 further 证实 confirm the 普遍性 universality of 我们 our 双 double-side 钝化 passivation approach, 方法 we 我们测试 tested two 两 more sets 组 of 不同 different 类型 types of 钙钛矿 perovskite 太阳能电池 solar cells using PMMA 钝化 passivation 层 layers. As 表现 demonstrated in the Figure 图 6a, all 所有电池 cells with 双 double-side 侧钝化 passivation exhibit 表现 much 多 higher V oc than the 相应 corresponding nonpassivated (control) 对照电池 cells, boosting 提高 their 它们 performance. 性能 The double-side 双侧钝化 passivation 还 also significantly 抑制 suppressed the J V hysteresis 滞后行为 behavior of 所有电池 all cells (see 见图 Figure 6b). The 详细 detailed J V curves 曲线 and 和 J V 参数 parameters are 还 also 提供 provided in 图 Figure S9 and 和 Table 表 S1 (Supporting 支持信息 Information). 3. 结论 Conclusion In summary, we 我们展示 demonstrated a 通用 universal 双 double-side 钝化 passivation 方法 method that passivates 钙钛矿 perovskite 太阳能电池 solar cells 包含 incorporating 超薄 ultrathin PMMA-films 薄膜 at the 钙钛矿 perovskite ETL 和 and 钙钛矿 perovskite HTL interfaces. 界面 The outstanding 出色钝化 passivation properties 特性 of the PMMA enabled 使 open 开 circuit 电压 voltages up to 1.22 V, which is 一 one of the 最高 highest 报告 reported for 1.6 ev bandgap 带隙钙钛矿 perovskite. A high PCE of 20.8% with 可忽略不计 negligible 滞后 hysteresis was 实现 achieved for the 冠军 champion 钝化 passivated 细胞 cells. 分析 Analysis of 钙钛矿 perovskite PMMA 相互作用 interactions 表明 reveals that the 钝化 passivation results from the Lewisbase 性质 properties of the 羰基 carbonyl (C O) 基团 group on the PMMA, which can 可以有效 effectively passivate under-coordinated 配位 lead 铅原子 atoms (Pb 2+ ), which are thought 被认 to cause 引起非辐射 nonradiative 复合 recombination at 钙钛矿 perovskite surfaces 表面和 and grain 界 boundaries. 这 This 发现 finding sheds new 新 light on 以前 previous 工作 work 涉及 involving PMMA 钝化 passivation 层 layers, and 并可能 may 提供 provide 额外 additional 解释 explanation for the 改进 improved 性能 performance of PMMA-templated 模板钙钛矿 perovskite 薄膜 films. [36,37] 虽然 Although 它提供 it provides 优异 excellent 界面 interface 钝化 passivation, PMMA is an 绝缘 insulating 聚合物 polymer so the 钝化 passivated 电池 cells did 有 have a 略有 slightly 降低 reduced 填充 fill-factor as a result of 增加 increased series 电阻 resistance. 这种 This was 减轻 mitigated on the ETL 方面 side by using a PMMA:PCBM 混合物 blend, as reported 前 previously, [43] 但 but 未来 future 发展 development of 新型 novel 导电 conducting 聚合物 polymers with C O 基团 groups 可以 may 导 lead to even 进一步 further efficiency 效率 gains. 4. 实验 Experimental Section 部分 实验 Experimental details 细节 are provided 提供 in the Supporting 支持信息 Information. 支持 Supporting 信息 Information 支持 Supporting 信息 Information is available from the Wiley 在线 Online 图书馆 Library 或 or from the author. 作者 致谢 Acknowledgements 这项 This 工作 work was supported 支持 by the Australian 澳大利亚政府 Government through the 澳大利亚 Australian 可再生 Renewable Energy 能源机构 Agency (ARENA) and 和 the 澳大利亚 Australian 研究 Research 理事会 Council. 责任 Responsibility for the 观点 views, information 信息 or 或建议 advice 表达 expressed herein 此处 is not 不接受 accepted by the 澳大利亚 Australian Government. 政府 J.P. 承认 acknowledges the 资金 funding 支持 support from 澳大利亚 Australian 纳米技术 Nanotechnology 网络 Network (ANN) 和 and 科 Department of 创新 Innovation, 工业 Industry, 科学 Science 和 and 研究 Research (DIISR). The research 研究 reported 报道 in 本 this 出版物 publication was supported by 资助 funding from 国王 King Abdullah 大学 University of Science and Technology (KAUST). The authors 作者感谢 thank Xavier Pita, 科学 scientific illustrator at 国王 King Abdullah 大学 University of Science 科学 and Technology (KAUST), for producing 图 Figure 1a in 本 this 文 paper. J.P. conceived the 个想法设计 idea, designed the 整体 overall 实验 experiments, and 并领导 led the 项目 project. J.P., T.D., H.S., and Y.W. 制备 prepared 和 and 表征 characterized the 钙钛矿 perovskite 电池装置 cell devices. J.I.K. and E.U. 进行 performed the TA 和 and TRPL measurements 测量和 and data 数据 analysis. 分析 F.L. 监督 supervised the TA and 和 TRPL 测量 measurements 和 and 分析 analysis. W.L., X.Y., and J. P. 进行 conducted the FTIR measurements 测量和 and 分析 analysis. W.L. performed 执行 the DFT 计算 calculation. T.D., H.S., and Y.W. 进行 conducted the PL imaging 成像测量 measurements. H.D. 进行 conducted the XRD 和 and SEM 测量 measurements. K.W. 进行 conducted the NMR 测量 measurements 和 and 分析 analysis. E.A. 进行 conducted the EQE 测量 measurements. J.P., J.I.K., K.J.W., K.R.C., F.L., S.D.W., and T.P.W. contributed to the 结果 results 分析 analysis 和 and 解释 interpretation. T.P.W. and S.D.W. 监督 supervised the 项目 project. J.P. wrote 写 the manuscript. 手稿所有作者 All authors contributed 贡献 to the 讨论 discussion of the 结果 results 和 and 修改 revision of the manuscript. 稿件 冲突 Conflict of 利益 Interest The authors 作者 declare 没有冲突 no conflict of 利益 interest (7 of 9)

8 Keywords 关键词 carbonyl 羰基基 group, 非辐射 nonradiative 复合 recombination, 钝化 passivation, 钙钛矿 perovskite solar 太阳能电池 cells, undercoordinated Pb atoms 原子 Received: April 22, 2018 修订 Revised: August 22, 2018 发表 Published 在线 online: [1] S. D. Stranks, G. E. Eperon, G. Grancini, C. Menelaou, M. J. Alcocer, T. Leijtens, L. M. Herz, A. Petrozza, H. J. Snaith, Science 2013, 342, 341. [2] G. Xing, N. Mathews, S. Sun, S. S. Lim, Y. M. Lam, M. Grätzel, S. Mhaisalkar, T. C. Sum, Science 2013, 342, 344. [3] M. M. Lee, J. Teuscher, T. Miyasaka, T. N. Murakami, H. J. Snaith, Science 2012, 338, 643. [4] W. Nie, H. Tsai, R. Asadpour, J.-C. Blancon, A. J. Neukirch, G. Gupta, J. J. Crochet, M. Chhowalla, S. Tretiak, M. A. Alam, H.-L. Wang, A. D. Mohite, Science 2015, 347, 522. [5] H. Zhou, Q. Chen, G. Li, S. Luo, T.-B. Song, H.-S. Duan, Z. Hong, J. You, Y. Liu, Y. Yang, Science 2014, 345, 542. [6] V. D Innocenzo, G. Grancini, M. J. Alcocer, A. R. S. Kandada, S. D. Stranks, M. M. Lee, G. Lanzani, H. J. Snaith, A. Petrozza, Nat. Commun. 2014, 5, [7] A. Kojima, K. Teshima, Y. Shirai, T. Miyasaka, J. Am. Chem. Soc. 2009, 131, [8] J. Burschka, N. Pellet, S.-J. Moon, R. Humphry-Baker, P. Gao, M. K. Nazeeruddin, M. Grätzel, Nature 2013, 499, 316. [9] J. W. Lee, D. J. Seol, A. N. Cho, N. G. Park, Adv. Mater. 2014, 26, [10] N. J. Jeon, J. H. Noh, W. S. Yang, Y. C. Kim, S. Ryu, J. Seo, S. I. Seok, Nature 2015, 517, 476. [11] Z. Wang, Q. Lin, F. P. Chmiel, N. Sakai, L. M. Herz, H. J. Snaith, Nat. Energy 2017, 2, [12] A. D. Jodlowski, C. Roldán-Carmona, G. Grancini, M. Salado, M. Ralaiarisoa, S. Ahmad, N. Koch, L. Camacho, G. De Miguel, M. K. Nazeeruddin, Nat. Energy 2017, 2, 972. [13] J. A. Christians, P. Schulz, J. S. Tinkham, T. H. Schloemer, S. P. Harvey, B. J. T. de Villers, A. Sellinger, J. J. Berry, J. M. Luther, Nat. Energy 2018, 3, 68. [14] M. Li, Z. K. Wang, Y. G. Yang, Y. Hu, S. L. Feng, J. M. Wang, X. Y. Gao, L. S. Liao, Adv. Energy Mater. 2016, 6, [15] W. Chen, Y. Wu, Y. Yue, J. Liu, W. Zhang, X. Yang, H. Chen, E. Bi, I. Ashraful, M. Grätzel, Science 2015, 350, 944. [16] Y. Hou, X. Du, S. Scheiner, D. P. McMeekin, Z. Wang, N. Li, M. S. Killian, H. Chen, M. Richter, I. Levchuk, N. Schrenker, E. Spiecker, T. Stubhan, N. A. Luechinger, A. Hirsch, P. Schmuki, H.-P. Steinruck, R. H. Fink, M. Halik, H. J. Snaith, C. J. Brabec, Science 2017, 358, [17] W. S. Yang, B. W. Park, E. H. Jung, N. J. Jeon, Y. C. Kim, D. U. Lee, S. S. Shin, J. Seo, E. K. Kim, J. H. Noh, S. I. Seok, Science 2017, 356, [18] N. Arora, M. I. Dar, A. Hinderhofer, N. Pellet, F. Schreiber, S. M. Zakeeruddin, M. Grätzel, Science 2017, 358, 768. [19] a) P. Schulz, ACS Energy Lett. 2018, 3, 1287; b) S. D. Stranks, ACS Energy Lett. 2017, 2, 1515; c) J.-P. Correa-Baena, W. Tress, K. Domanski, E. H. Anaraki, S. -H. Turren-Cruz, B. Roose, P. P. Boix, M. Grätzel, M. Saliba, A. Abate, A. Hagfeldt, Energy Environ. Sci. 2017, 10, 1207; d) K. K. Wong, A. Fakharuddin, P. Ehrenreich, T. Deckert, M. Abdi-Jalebi, R. H. Friend, L. Schmidt-Mende, J. Phys. Chem. C 2018, 122, 10691; e) M. Stolterfoht, C. M. Wolff, J. A. Marquez, S. Zhang, C. J. Hages, D. Rothhardt, S. Albrecht, P. L. Burn, P. Meredith, T. Unold, D. Neher, Nat. Energy 2018, [20] W. Tress, Adv. Energy Mater. 2017, 7, [21] N. K. Noel, A. Abate, S. D. Stranks, E. S. Parrott, V. M. Burlakov, A. Goriely, H. J. Snaith, ACS Nano 2014, 8, [22] I. A. Shkrob, T. W. Marin, J. Phys. Chem. Lett. 2014, 5, [23] W.-J. Yin, T. Shi, Y. Yan, Appl. Phys. Lett. 2014, 104, [24] a) Z. Xiao, Y. Yuan, Y. Shao, Q. Wang, Q. Dong, C. Bi, P. Sharma, A. Gruverman, J. Huang, Nat. Mater. 2015, 14, 193; b) H. Uratani, K. Yamashita, J. Phys. Chem. Lett. 2017, 8, 742. [25] A. Abate, M. Saliba, D. J. Hollman, S. D. Stranks, K. Wojciechowski, R. Avolio, G. Grancini, A. Petrozza, H. J. Snaith, Nano Lett. 2014, 14, [26] B. Chen, M. Yang, S. Priya, K. Zhu, J. Phys. Chem. Lett. 2016, 7, 905. [27] W. Tress, N. Marinova, T. Moehl, S. M. Zakeeruddin, M. K. Nazeeruddin, M. Grätzel, Energy Environ. Sci. 2015, 8, 995. [28] F. Huang, L. Jiang, A. R. Pascoe, Y. Yan, U. Bach, L. Spiccia, Y.-B. Cheng, Nano Energy 2016, 27, 509. [29] a) B. Chaudhary, A. Kulkarni, A. K. Jena, M. Ikegami, Y. Udagawa, H. Kunugita, K. Ema, T. Miyasaka, ChemSusChem 2017, 10, 2473; b) L. Zuo, H. Guo, S. Jariwala, N. De Marco, S. Dong, R. DeBlock, D. S. Ginger, B. Dunn, M. Wang, Y. Yang, Sci. Adv. 2017, 3, e [30] C.-C. Zhang, M. Li, Z.-K. Wang, Y.-R. Jiang, H.-R. Liu, Y.-G. Yang, X.-Y. Gao, H. Ma, J. Mater. Chem. A 2017, 5, [31] H. Yoon, S. M. Kang, J.-K. Lee, M. Choi, Energy Environ. Sci. 2016, 9, [32] Y. Shao, Z. Xiao, C. Bi, Y. Yuan, J. Huang, Nat. Commun. 2014, 5, [33] C. Tao, S. Neutzner, L. Colella, S. Marras, A. R. S. Kandada, M. Gandini, M. De Bastiani, G. Pace, L. Manna, M. Caironi, C. Nertarelli, A. Petrozza, Energy Environ.Sci. 2015, 8, [34] Y. Zhao, W. Zhou, W. Ma, S. Meng, H. Li, J. Wei, R. Fu, K. Liu, D. Yu, Q. Zhao, ACS Energy Lett. 2016, 1, 266. [35] A. Agresti, S. Pescetelli, B. Taheri, A. E. Del Rio Castillo, L. Cina, F. Bonaccorso, A. Di Carlo, ChemSusChem 2016, 9, [36] D. Bi, C. Yi, J. Luo, J.-D. Décoppet, F. Zhang, S. M. Zakeeruddin, X. Li, A. Hagfeldt, M. Grätzel, Nat. Energy 2016, 1, [37] S. Masi, A. Rizzo, F. Aiello, F. Balzano, G. Uccello-Barretta, A. Listorti, G. Gigli, S. Colella, Nanoscale 2015, 7, [38] F. Wang, A. Shimazaki, F. Yang, K. Kanahashi, K. Matsuki, Y. Miyauchi, T. Takenobu, A. Wakamiya, Y. Murata, K. Matsuda, J. Phys. Chem. C 2017, 121, [39] H. Tan, A. Jain, O. Voznyy, X. Lan, F. P. G. de Arquer, J. Z. Fan, R. Quintero-Bermudez, M. Yuan, B. Zhang, Y. Zhao, F. Fan, P. Li, L. Quan, Y. Zhao, Z.-H. Lu, Z. Yang, S. Hoogland, E. H. Sargent, Science 2017, 355, 722. [40] M. Saliba, T. Matsui, K. Domanski, J.-Y. Seo, A. Ummadisingu, S. M. Zakeeruddin, J.-P. Correa-Baena, W. R. Tress, A. Abate, A. Hagfeldt, M. Gratzel, Science 2016, 354, 206. [41] E. H. Anaraki, A. Kermanpur, L. Steier, K. Domanski, T. Matsui, W. Tress, M. Saliba, A. Abate, A. Abate, M. Grätzel, A. Hagfeldt, J.-P. Correa-Baena, Energy Environ. Sci. 2016, 9, [42] J. Peng, T. Duong, X. Zhou, H. Shen, Y. Wu, H. K. Mulmudi, Y. Wan, D. Zhong, J. Li, T. Tsuzuki, K. J. Weber, K. R. Catchpole, T. P. White, Adv. Energy Mater. 2017, 7, [43] J. Peng, Y. Wu, W. Ye, D. A. Jacobs, H. Shen, X. Fu, Y. Wan, T. Duong, N. Wu, C. Barugkin, H. T. Nguyen, D. Zhong, J. Li, T. Lu, Y. Liu, M. N. Lockrey, K. J. Weber, K. R. Catchpole, T. P. White, 白色 Energy 能量 Environ. Sci. 2017, 10, [44] M. I. Dar, M. Franckevičius, N. Arora, K. Redeckas, M. Vengris, V. Gulbinas, S. M. Zakeeruddin, M. Grätzel, Chem. Phys. Lett. 2017, 683, (8 of 9)

9 [45] J. M. Richter, M. Abdi-Jalebi, A. Sadhanala, M. Tabachnyk, J. P. Rivett, L. M. Pazos-Outón, K. C. Gödel, M. Price, F. Deschler, R. H. Friend, Nat. Commun. 2016, 7, [46] J. M. Ball, A. Petrozza, Nat. Energy 2016, 1, [47] L. M. Herz, Annu. Rev. Phys. Chem. 2016, 67, 65. [48] C. L. Davies, M. R. Filip, J. B. Patel, T. W. Crothers, C. Verdi, A. D. Wright, R. L. Milot, F. Giustino, M. B. Johnston, L. M. Herz, Nat. Commun. 2018, 9, 293. [49] Y. Yang, M. Yang, D. T. Moore, Y. Yan, E. M. Miller, K. Zhu, M. C. Beard, Nat. Energy 2017, 2, [50] A. T. Hubbard, 哈伯德 Encyclopaedia of 表面 Surface, 胶体 Colloid Science 科学 P.77, Vol. 1, Marcel Dekker, New York [51] T. Duong, Y. Wu, H. Shen, J. Peng, X. Fu, D. Jacobs, E-C. Wang, T. C. Kho, K. C. Fong, M. Stocks, E. Franklin, A. Blakers, N. Zin, K. Mclntosh, W. Li, Y.-B. Cheng, T. P. White, K. Weber, K. Catchpole, Adv. Energy Mater. 2017, 7, (9 of 9)