Composite electron transport layer for efficient N-I-P type monolithic perovskite/silicon tandem solar cells with high open-circuit voltage

Perovskite/silicon tandem solar cells (PSTSCs) have exhibited huge technological potential for breaking the Shockley-Queisser limit of single-junction solar cells. The efficiency of P-I-N type PSTSCs has surpassed the single-junction limit, while the performance of N-I-P type PSTSCs is far below the theoretical value. Here, we developed a composite electron transport layer for N-I-P type monolithic PSTSCs with enhanced open-circuit voltage (V-OC) and power conversion efficiency (PCE). Lithium chloride (LiCl) was added into the tin oxide (SnO2) precursor solution, which simultaneously passivated the defects and increased the electron injection driving force at the electron transfer layer (ETL)/perovskite interface. Eventually, we achieved monolithic PSTSCs with an efficiency of 25.42% and V-OC of 1.92 V, which is the highest PCE and V-OC in N-I-P type perovskite/Si tandem devices. This work on interface engineering for improving the PCE of monolithic PSTSCs may bring a new hot point about perovskite-based tandem devices. (C) 2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

Perovskite/silicon tandem solar cells have shown great potential in surpassing the efficiency limits of single-junction solar cells. By engineering the interface of N-I-P type monolithic PSTSCs, a composite electron transport layer was developed to achieve higher efficiency and open-circuit voltage than before.