High-Performance Planar Perovskite Solar Cells with Negligible Hysteresis Using 2,2,2-Trifluoroethanol-Incorporated SnO2

Abstract

Summary An efficient electron transport layer (ETL) between the perovskite absorber and the cathode plays a crucial role in obtaining high-performance planar perovskite solar cells (PSCs). Here, we incorporate 2,2,2-trifluoroethanol (TFE) in the commonly used tin oxide (SnO 2 ) ETL, and it successfully improves the power conversation efficiency (PCE) and suppresses the hysteresis of the PSCs: the PCE is increased from 19.17% to 20.92%, and the hysteresis is largely reduced to be almost negligible. The origin of the enhancement is due to the improved electron mobility and optimized work function of the ETL, together with the reduced traps in the perovskite film. In addition, O 2 plasma is employed to treat the surface of the TFE-incorporated SnO 2 film, and the PCE is further increased to 21.68%. The concept here of incorporating organic small molecules in the ETL provides a strategy for enhancing the performance of the planar PSCs.

Dopant‐Free, Amorphous–Crystalline Heterophase SnO2Electron Transport Bilayer Enables >20% Efficiency in Triple‐Cation Perovskite Solar Cells

“…Instead, the Bi‐SnO 2 film exhibited the highest transmittance in the UV‐range, which is likely due to the stronger light propagation and photon oscillation at the ITO/SnO 2 interface with increasing film thickness. [ 38 ] To further verify this, a simple finite‐difference time‐domain simulation has been conducted to calculate the optical transmittance spectra of the nanostructured SG‐SnO 2 , NP‐SnO 2 , and Bi‐SnO 2 films on ITO substrate. The detailed simulation method and input parameters can be found in Supporting Information.…”

Recent Progresses on Defect Passivation toward Efficient Perovskite Solar Cells

“…This result may stem from that Sn 4+ metal atom coordinate with two more mono‐dentate halogen ligands in Cl 2 /Br 2 than tin(II) bis(acetylacetonate). Moreover, Luan et al also observed that oxygen plasma treatment of the SnO 2 film surface can significantly improve device performance, possibly attributed to changes in surface roughness and work function …”

Chlorinated Fullerene Dimers for Interfacial Engineering Toward Stable Planar Perovskite Solar Cells with 22.3% Efficiency

“…[ 9 ] TiO 2 and SnO 2 , the most promising ETMs in planar PSCs, are not always ideal for efficient charge extraction due to their low electron mobility, large energy barrier, and vast uncoordinated defect sites. [ 10 ]…”