Supplementry informtion Supplementry Mteril (ES) for Soft Mtter The development of nnoscle morphology in polymer:fullerene photovoltic lends during solvent csting To Wng, * Aln D. F. Dunr, Pul A. Stniec, Andrew J. Person, Pul E. Hopinson, c J Emyr McDonld, d Smuele Lilliu, d Clire Pizzey, e Nichols J. Terrill, e Athene M. Donld, c Anthony J. Ryn, f Richrd A. L. Jones * nd Dvid G. Lidzey * Deprtment of Physics nd Astronomy, University of Sheffield, Sheffield, S3 7RH, UK Deprtment of Chemicl nd Process Engineering, University of Sheffield, Sheffield S1 3JF, UK c Cvendish Lortory, Deprtment of Physics, University of Cmridge, Cmridge CB3 0HE, UK d Deprtment of Physics nd Astronomy, Crdiff University, Crdiff CF4 3YB, UK e Dimond Light Source Ltd, Dimond House, Hrwell Science nd nnovtion Cmpus, Didcot, Oxfordshire OX11 0DE, UK f Deprtment of Chemistry, University of Sheffield, Sheffield, S3 7HF, UK e-mil: towng@sheffield.c.u; r..l.jones@sheffield.c.u; d.g.lidzey@sheffield.c.u 1
1. A schemtic crtoon of in-situ ellipsometry nd G-XS system. ellipsometer X-ry detector Chmer X-ry source Stge Figure S1 3D crtoon of the in-situ system setup.. Spectroscopic dt recorded during the drying of P3HT/PCBM lend cst from solution of TCB. Figure S shows typicl ellipsometry dt recorded s function of time during the drying of P3HT:PCBM film. Here, the film ws cst using doctor lde from TCB (50 mg/ml) solution onto Si wfer onto sustrte held t 30 o C.
Figure S Spectroscopic dt recorded during the drying of P3HT/PCBM lend cst from solution of TCB t sustrte temperture of 30 o C. nterference resulting from the pssge of the doctor lde through the ellipsometer em pth is not shown. 3. Clculting the chnge in film thicness using Cuchy model. The chnge in film thicness during drying ws determined using Cuchy model tht ws fit to ellipsometry dt over the wvelength-rnge 700 to 1000 nm, where the film hs negligile sornce. The Cuchy model hs een utilized to descrie the dispersion of the complex refrctive index (refrctive index n, nd extinction coefficient ) in trnsprent dielectric. n trnsprent spectrl region, the extinction coefficient is zero, wheres the refrctive index is represented y slowly vrying function of wvelength λ s: B C n = A + +... 4 λ λ Where A, B nd C re fit prmeters. To improve the fit, non-uniformity prmeter ws dded to the Cuchy model. The est fit ws identified y minimizing the men squre error (MSE) defined y the following eqution: MSE = tn(ψ exp tn(ψ cl ) + cos(δ exp cos(δ cl ) σ tn(ψ) σ cos(δ) N M 1 Here, Ψ nd Δ re the rtios of the mplitude of light nd its reltive-phse efore nd fter reflection from the film/sustrte respectively with the suscripts exp nd cl signifying experimentlly nd clculted vlues. The terms N nd M represent the numer of wvelengths t which mesurements were performed nd the numer of prmeters used in the fitting process, respectively. Vlues of Ψ nd Δ recorded t. 3
three different times during the drying process (1.8, 10.3 nd 5.3 s fter the film een cst) plotted s function of wvelength re shown in Figures S3 to c. n ech cse, the dshed curves plotted over the rnge 700 to 1000 nm re fits to the dt using the Cuchy model. Spectroscopic Dt t 1.8 s Spectroscopic Dt t 10.3 s c Spectroscopic Dt t 5.3 s Figure S3 Ellipsometry dt (Ψ nd Δ; red nd green respectively) s function of wvelength t different drying times. Curves fits over the rnge from 700 nm to 1000 nm using Cuchy model re shown s dshed line. 4
4. Clculting the opticl constnts vi B-spline fit. The film thicness t ech time during film drying ws determined using the Cuchy model s descried in the ove. This vlue ws then put into B-spline model to fit the opticl constnts (n nd ) over the opticl rnge corresponding to strong opticl sorption of the P3HT / PCBM thin film (400 to 700 nm). This fitting ws performed with 10 nm wvelength resolution. We found tht the MSE during the B-spline fit went from ~ 9 in wet film to ~ 3 s the film dried. Figure S4 shows typicl plot of the extinction coefficient etween 400 nd 700 nm determined from wet P3HT:PCBM film. A chrcteristic pe is oserved t 460 nm tht corresponds to the sorption of solvted (un-ggregted) P3HT molecules. Figure S4 shows typicl extinction coefficient plot of dry (polycrystlline) P3HT:PCBM film. Chrcteristic P3HT sorption pes t 517, 550 nd 605 nm (the 0-, 0-1 nd 0-0 virtionl nd electronic modes respectively) cn e resolved. Figure S4 Extinction coefficient determined from wet (S4) nd dry (S4) P3HT/PCBM film. 5. The evolution of the extinction coefficient of P3HT:PCBM film cst from CB solution t sustrte temperture of 40 nd 50 o C. The vrition of extinction coefficient s function of ϕ P3HT:PCBM. 5
mx 550 mx 550 0 5 10 15 Time (s) 0 5 10 15 Time (s) c 30 o C 40 o C 50 o C mx d 30 o C 40 o C 50 o C mx 550 550 1.0 ϕ P3HT:PCBM 1.0 ϕ P3HT:PCBM Figure S5 nd plots the chnge in the extinction coefficient of P3HT:PCBM film cst from CB t temperture of 40 nd 50 o C respectively. Prts c nd d show the evolution of vs. ϕ P3HT:PCBM in films cst from TCB nd CB respectively t rnge of tempertures s indicted in the figure. 6. X-ry scttering of P3HT:PCBM A D GWAXS of P3HT:PCBM film is shown in S6. Here, the primry [100], secondry [00], nd tertiry [300] scttering pes of P3HT lmell re detected in the out-of-plne direction. An in-plne [010] pe corresponding to π-stced P3HT molecules is lso detected. The PCBM is pprent from the presence of rod nd diffuse ring. Smoothed [100] profiles otined y G-XS show the evolution of P3HT crystlliztion during the film growth process. 6
q z (A -1 ).0 1.5 1.0 0.5 (010) (300) (00) (100) PCBM ring 5 0.30 0.35 0 5 0.50 Q(A -1 ) 5 4 nitensity (.u.) 3 1.0 1.5 1.0 0.5 q x (A -1 ) Figure S6, GWAXS of P3HT:PCBM lend mesured t 16, Dimond Light Source., The evolution of the P3HT [100] X-ry scttering pe during drying of the film, fter een smoothed to clerly show the growth of this feture. 7. Reltion etween the mesured extinction coefficient nd crystllinity There is n pproximtely liner dependence of the extinction coefficient on the P3HT crystllinity s determined from the intensity of the [100] scttering pe. This dt-set ws constructed y performing X-ry scttering nd ellipsometry mesurements on ex-situ prepred P3HT:PCBM lend films cst using doctor lding. The films were cst using different solvents onto sustrtes t different tempertures, resulting in films hving rnge of crystllinities. 0.5 Exp dt Liner fit 0.3 0.1 40 60 80 100 X-ry crystllinity (%) (.u.) Figure S7 Reltion etween extinction coefficient () in P3HT nd the crystllinity clculted from the [100] pttern. 7