Low-temperature-processed metal oxide electron transport layers for efficient planar perovskite solar cells

As a promising photovoltaic technology, perovskite solar cells (pero-SCs) have developed rapidly over the past few years and the highest power conversion efficiency is beyond 25%. Nowadays, the planar structure is universally popular in pero-SCs due to the simple processing technology and low-temperature preparation. Electron transport layer (ETL) is verified to play a vital role in the device performance of planar pero-SCs. Particularly, the metal oxide (MO) ETL with low-cost, superb versatility, and excellent optoelectronic properties has been widely studied. This review mainly focuses on recent developments in the use of low-temperature-processed MO ETLs for planar pero-SCs. The optical and electronic properties of widely used MO materials of TiO2, ZnO, and SnO2, as well as the optimizations of these MO ETLs are briefly introduced. The commonly used methods for depositing MO ETLs are also discussed. Then, the applications of different MO ETLs on pero-SCs are reviewed. Finally, the challenge and future research of MO-based ETLs toward practical application of efficient planar pero-SCs are proposed.

Automated summary

Perovskite solar cells have rapidly developed with efficiencies exceeding 25%, particularly the widely studied metal oxide electron transport layer (ETL) known for its low-cost and excellent optoelectronic properties. The planar structure in PSCs is popular due to simple processing methods and low-temperature preparation, with the focus on recent advancements in using low-temperature-processed MO ETLs.