Efficient Inorganic Perovskite Light-Emitting Diodes with Polyethylene Glycol Passivated Ultrathin CsPbBr 3 Films

Transcription

1 Supporting information Efficient Inorganic Perovskite Light-Emitting Diodes with Polyethylene Glycol Passivated Ultrathin CsPbBr 3 Films Li Song,, Xiaoyang Guo, *, Yongsheng Hu, Ying Lv, Jie Lin, Zheqin Liu,, Yi Fan, and Xingyuan Liu *, State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun , China University of Chinese Academy of Sciences, Beijing , China Corresponding Author: * guoxy@ciomp.ac.cn; liuxy@ciomp.ac.cn S1

2 Figure S1. (a) Cross-sectional AFM profile of the scratched PEDOT:PSS film. (b) Cross-sectional AFM profile of the scratched PEDOT:PSS/PEG:CsPbBr 3 film. S2

3 Figure S2. Relationship between EQE and current density for the PeLEDs with different PEG:CsPbBr 3 (CsBr:PbBr 2 molar ratio of 1.4:1) weight ratios. S3

4 Figure S3. XRD patterns of the CsPbBr 3 and PEG:CsPbBr 3 films. S4

5 Figure S4. (a) J-V (b) L-V (c) CE-V and (d) EQE-V curves for the PeLEDs with different CsBr:PbBr 2 molar ratios at fixed PEG doping weight ratio of 3.4%. S5

6 Figure S5. Time-resolved PL decay curves for CsPbBr 3 and PEG:CsPbBr 3 (CsBr:PbBr 2 molar ratio of 1.86) films. S6

7 Figure S6. (a) J-V-L, (b) current efficiency-v, (c) EQE-V and (d) EL curves for the red PeLEDs with and without PEG doping. The CsBr:PbI 2 molar ratio in CsPbBr x I 3-x is 1.7:1 and the weight ratio of PEG: CsPbBr x I 3-x is 4.08%. Calculation of the weight ratio of PEG: CsPbBr x I 3-x : Perovskite solution (CsBr (86 mg) and PbI 2 (110 mg) in 1 ml DMSO) and PEG solution were first prepared as stock solutions. Before spin coating, these two solutions were mixed (perovskite: PEG= 10: 4 v/v) to form transparent precursor solution. The optimized PEG concentration is 20 mg/ml for the PEG: CsPbBr x I 3-x PeLED. Therefore, the weight ratio of PEG: CsPbBr x I 3-x is 4.08%. S7

8 Table S1. The PLQYs for CsPbBr 3 films with different CsBr:PbBr 2 molar ratios. CsBr:PbBr 2 1.4:1 1.54:1 1.69:1 1.77:1 1.86:1 1.95:1 PLQY (%) S8

9 Table S2. PL lifetime of CsPbBr 3 and PEG:CsPbBr 3 films with CsBr:PbBr 2 molar ratio of 1.4:1 and 1.86:1, respectively. CsBr:PbBr 2 molar ratio 1.4:1 1.86:1 PEG weight ratio (%) Fitting model (exponential decay) Tri- (ns) (%) (ns) (%) (ns) (%) (ns) The decay curves for all the perovskite films can be best represented by the tri-exponential model : A(t)= exp(-t/τ 1 )+ exp(-t/τ 2 )+ exp(-t/τ 3 ) The multi-exponential decay curve reflects the presence of trap centers as the reference reported. 1, 2 The fastest decay component (τ 1 ) may relate to well-known surface or bulk defects assisted recombination. The second fastest decay component (τ 2 ) is the bimolecular recombination in the CsPbBr 3 bulk crystal and the slowest decay (τ 3 ) is relevant to the radiative recombination of free-carriers. The average life time was calculated by the equation: τ avg =τ 1 +τ 2 +τ 3 S9

10 Table S3. Summary of the representative CsPbBr 3 based PeLEDs. Perovskite emitter/thickness (nm) CsPbBr 3 thin film/30 nm CsPbBr 3 thin film/70 nm EL peak ( nm) V on (V) L max (cd/m 2 ) Max. EQE (%) Max. CE (cd/a) CsPbBr 3 thin film/na 527 NA CsPbBr 3 thin film/na 528 3V 407 NA CsPbBr 3 thin film/ NA CsPbBr 3 NCs/ 40 nm CsPbBr 3 QDs/ NA Ref This work QDs (quantum dots), NCs (nanocrystals), V on (turn on voltage), L max (maximum luminance), NA (not available) S10

11 Table S4. Parameters for the CsPbBr x I 3-x red PeLEDs. The CsBr:PbI 2 molar ratio in CsPbBr x I 3-x is 1.7:1 and the weight ratio of PEG: CsPbBr x I 3-x is about 4%. Pervoskite L max Max. CE Max. EQE V on L max emitter (cd/m 2 ) (cd/a) (%) (V) (V) CsPbBr x I 3-x * * PEG:CsPbBr x I 3-x * * S11

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