Carbon‐Double‐Bond‐Free Printed Solar Cells from TiO₂/CH₃NH₃PbI₃/CuSCN/Au: Structural Control and Photoaging Effects

Abstract

Carbon double bond-free printed solar cells have been fabricated with the structure <F-doped SnO2 (FTO)/dense TiO2/nanocrystalline TiO2/CH3NH3PbI3/Au> and <FTO/dense TiO2/nanocrystalline TiO2/CH3NH3PbI3/CuSCN/Au>, in which CuSCN acts as a hole conductor. The thickness of the CH3NH3PbI3 layer is controlled by a hot air flow during spin coating. The best conversion efficiency (4.86%) is obtained with <FTO/dense TiO2/nanocrystalline TiO2/thin CH3NH3PbI3 (hot-air dried)/CuSCN/Au>. However, a thick CH3NH3PbI3 layer on CuSCN is better for light-exposure stability (100 mW cm(-2) AM 1.5) when not encapsulated. Without the CuSCN coverage, the black CH3NH3PbI3 crystal changes to yellow during the light-exposure stability test, which is due to the transformation of the CH3NH3PbI3 perovskite crystal into hexagonal PbI2.

Transamidation of dimethylformamide during alkylammonium lead triiodide film formation for perovskite solar cells

“…The reaction is accelerated on TiO 2 substrates that were prepared with an alcohol and annealed at 500-700°C, 35 which is particularly relevant to PSC. 3,8,10,11,13,14,25,32,35,36,41,42 Alternatively, transamidation can also be catalyzed by water 21 or an acid (e.g., HI) 22 ( Fig. 1).…”

“…5,7 Diverse strategies have improved film morphology of methylammonium lead halide (MAPbX 3 ) perovskites, e.g., increasing crystal grain size (correlated to the strength of x-ray diffraction peaks) and film uniformity (measured by atomic force microscopy). [8][9][10] However, improved morphology has not directly translated into improved PCE or reduced perovskite degradation, suggesting that the chemical nature of a film plays a significant role. Some recent recordholding perovskite solar cells reduced 11 or eliminated 2 N,N-dimethylformamide (DMF) and showed corresponding improvement in reproducibility and stability, suggesting that DMF may be related to the underlying causes.…”

High-efficiency perovskite solar cells improved with low-cost orthorhombic Cu2ZnSnS4 as the hole-transporting layer

“…For comparison, a reference PSC device based on a spiro-OMeTAD HTL was also fabricated following the procedure reported in the literature. 10 Finally, an Ag electrode was thermally evaporated as an electrode. All of the layers were fabricated inside an N 2 -filled glove box.…”

“…6 Different types of hole-transport materials (HTMs) such as poly(triarylamine)(PTAA), poly (3-hexylthiophee-2,5-diyl(P3HT), poly[2,6-(4,4-bis(2-ethylhexyl)-4Hcyclopenta[2,1-b;3,4-b']dithiophene)-alt-4,7-(2,1,3-be nzothiadiazole)(PCPDTBT), spiro-OMeTAD, poly (3-hexylthiophene-2,5-diyl) (P3HT), 4-(diethylamino)-benzaldehyde diphenylhydrazone (DEH), MoO 3 and CuSCN were developed to fabricate perovskite-solar-cell devices. [7][8][9][10] Organic HTMs called spiro-OMeTAD and PTAA have been widely used and achieved a PCE reaching 20.54 %. However, these materials are easy to degrade and expensive for fabricating solar cells because of their complicated synthetic procedures and highpurity requirement.…”

“…For instance, Seigo Ito et al used CuSCN as the HTM for solar cells and achieved a PCE of 4.86 %, which was lower than that obtained for the spiro-OMeTAD HTM-based device. 10 After that, the CuI HTM was also applied by Qin et al to fabricate high-efficiency and stable perovskite solar cells using a low-temperature solution-process deposition method, leading to a high PCE of 6.6 %.…”