Low-pressure treatment of CuSCN hole transport layers for enhanced carbon-based perovskite solar cells

Low-cost and stable carbon-based hole-conductor layers have attained especial interest in perovskite solar cells (PSCs). Because the carbon-based hole-conductor-free PSCs usually have the serious problems of low power conversion efficiency (PCE) and obvious current hysteresis. Herein, we introduced CuSCN hole transfer layers (HTLs) with low pressure treatment (LPT) into carbon-based PSCs to improve the performance and reduce the hysteresis. After being coated, the CuSCN layers were immediately transferred to low-pressure environment for vaporizing the polar diethyl sulfide (DES) without destruction of perovskite films. Our champion device engineered through carbon-based PSCs with low-pressure-treated CuSCN HTLs achieved power conversion efficiency (PCE) of 13.05%, compared with 10.6% of that without CuSCN layer. Importantly, the incorporating CuSCN HTLs can build energy level cascade to obviously reduce the current hysteresis due to the balanced electrode-hole extraction ability. Moreover, the stability of the device was obviously improved due to the hydrophobic nature of CuSCN layer. While the low-temperature (similar to 20. degrees C and 50 degrees C) volatilizing DES in CuSCN layer destroyed the perovskite films under room pressure, which reduced the PCE to 8.6% and 9.9%, respectively. Thereby, this work highlights the advantages of incorporating low-pressure-treated CuSCN HTLs into carbon-based PSCs with improving performance and reducing current hysteresis, which will promote the future industrial application.

Automated summary

The study introduced CuSCN hole transfer layers (HTLs) with low pressure treatment (LPT) into carbon-based PSCs to increase the power conversion efficiency (PCE) and reduce current hysteresis. The incorporation of CuSCN HTLs led to an improvement in PCE and reduced current hysteresis, highlighting the potential for future industrial applications.