LAUSR

The electron transport layer plays a key role in affecting the charge dynamics and photovoltaic parameters in perovskite solar cells. Compared to other counterparts, SnO2 has unique advantages such as low temperature fabrication and high electron extraction ability, and it receives extra attentions from the research community since the first report. Planar‐type perovskite solar cells based on SnO2 exhibit a simple architecture and state of art device can achieve a power conversion efficiency of over 23%, which can compete with traditional devices using mesoporous TiO2. The modification engineering of SnO2 has contributed significantly to the enhanced device performance during the past years. There is still great potential for further improvement in the efficiency and long‐term stability. Herein recent advances toward modifying the optoelectronic properties of SnO2 from the perspective of the optimization strategies are summarized and the remaining challenges as well as opportunities for future research are discussed. The continuous efforts dedicated to this exciting field may pave the way for developing commercial perovskite solar cells.