Choline Chloride-Modified SnO₂ Achieving High Output Voltage in MAPbI₃ Perovskite Solar Cells

Abstract

Choline chloride as a photosynthesis promoter is important for increasing plant yield, and we have found that it has a similar effect in perovskite solar cells (PSCs). Here, we propose the innovation of using molecular self-assembly methods to produce a choline chloride monolayer on the surface of the SnO 2 ; this monolayer works as a passivation layer that reduces the surface oxygen vacancies and improves the performance of CH 3 NH 3 PbI 3 (MAPbI 3 ) PSCs. The MAPbI 3 PSC based on SnO 2 modified by choline chloride (Chol-SnO 2 ) electron transport layer (ETL) achieves an optimal power conversion efficiency (PCE) of 18.90% under one solar illumination. The PCE is increased by 10−25% compared to the device without modification, and hysteresis is significantly reduced by eliminating the charge accumulation between the interface of the perovskite and ETL. More importantly, the MAPbI 3 PSC based on Chol-SnO 2 ETL exhibits a higher open-circuit voltage (V OC ) of 1.145 V compared to the control device (1.071 V). This work provides a very simple and effective way to improve PSC performance, which has long-term significance for the sustainable development of energy.

Precursor Engineering of the Electron Transport Layer for Application in High‐Performance Perovskite Solar Cells

“…The reduced R co values exhibited by PSCs utilizing SnO 2 -MACl/FACl-based ETLs suggest that SnO 2 -MACl/FACl enhanced the charge transfer ability of the cells in comparison to the pure SnO 2 samples. [42,50] To investigate the stability of the PSC devices, a sample of each composition was stored in a glove box to simulate the aging process. Figure 6d shows the resultant PCEs of all three PSCs.…”

“…The survey XPS profiles in Figure 3b confirm the presence of N, Cl, Sn, and O in the SnO 2 ‐MACl/FACl samples. [ 49 , 50 ] Figure 3c compares the Cl 2p XPS profiles of the SnO 2 ‐MACl, SnO 2 ‐FACl, and pure SnO 2 samples. The results suggest that SnO 2 was successfully modified through the addition of MACl/FACl.…”

“…The Sn 3d XPS profiles in Figure 3d show that the Sn 3d double peaks arising from the SnO 2 ‐MACl and SnO 2 ‐FACl samples undergo a shift to a higher photoelectron binding energy in comparison to the pure SnO 2 sample, suggesting that the introduction of Cl in the sample induced a negative charge in the vicinity of the Sn atom. [ 42 , 50 ] Figure S7 , Supporting Information, shows the UV–Vis absorption spectra of perovskite films deposited on SnO 2 ‐MACl, SnO 2 ‐FACl, and pure SnO 2 ETLs. It can be seen that the addition of MACl and FACl will not affect the absorption edge and absorption intensity of perovskite films.…”

“…The reduced R co values exhibited by PSCs utilizing SnO 2 ‐MACl/FACl‐based ETLs suggest that SnO 2 ‐MACl/FACl enhanced the charge transfer ability of the cells in comparison to the pure SnO 2 samples. [ 42 , 50 ]…”

Effect of surface modification of nickel oxide hole‐transport layer via self‐assembled monolayers in perovskite solar cells

“…[9][10][11][12][13] Specifically, in PSCs, SAMs have also been used, though more often in the n-i-p device configuration, and considerable improvements in the performance were reported. [14][15][16][17] The SAM formation process typically involves immersion of the substrate in a solution of modifying molecules. [18][19][20] In the n-i-p configuration, the SAM is formed on the surface of electrontransporting layer, such as TiO 2 , to realize its effect on the device performance.…”