Reducing damage of sputtering and improving conductivity of transparent electrodes for efficient semi-transparent perovskite solar cells

Abstract

Sputtered indium tin oxide (ITO) is widely used as top electrode in semi-transparent and tandem perovskite solar cell. However, damage of sputtering to under layers and limited conductivity of ITO are still the two main obstacles that hinder further performance improvement of the devices. In this work, the effects and mechanism of sputtering damage and poor conductivity of ITO are investigated based on a traditional perovskite solar cell with bathocuproine (BCP) buffer layer. In order to suppress the sputtering damage, tin oxide (SnO2) is deposited on C60 to replace BCP buffer layer. However, it is found that the deposition of SnO2 on the non-reactive C60 by atomic layer deposition will result in island growth of SnO2 film, which is the key reason for large dark current in solar cells. Fortunately, the phenomenon is inhibited by decorating C60 surface with WO3 thin film. In order to improve the conductivity of the transparent electrode, an ITO/Au/ITO multilayer architecture is designed. The fill factor (FF) and power conversion efficiency (PCE) of the semi-transparent solar cells (ST-PSCs) with the modified buffer layer and electrodes reached 76.4% and 17.62%, respectively, showing an improvement of FF and PCE when it compared to the device with BCP buffer layer and ITO electrode. It is revealed that the optimization also benefits for the increase of short circuit current of the solar cells. These results provide new strategies for damage reduction of sputtering and performance improvement of ST-PSCs.

Phase transition mechanism of CsPbI2Br perovskite films induced by moisture

“…due to their long diffusion length, small optical band gap, high optical absorption coefficient, and low exciton binding energy, etc [1][2][3][4][5]. Among them, CH 3 NH 3 PbI 3 and CH(NH 2 ) 2 PbI 3 have been thoroughly studied and many exciting results have been achieved [6][7][8][9][10]. However, the volatile organic cations in these materials will seriously deteriorate their stability under environmental conditions [11][12][13][14][15][16].…”