Effective strategy for stabilized perovskite solar cells using tandem architecture

Organometal trihalide perovskite material is an exciting class of photovoltaic material with good performance and simple fabrication process that can be adopted by low-cost manufacturable technologies. Unfortunately, such technology is haunted by stability issues for long term applications. To address this issue, recent studies generally trade performance for stability by applying a filter to eliminate UV and blue illumination. Herein, we report our success in using a-Si/perovskite architecture, in which the a-Si is not only part of the device, but also an effective UV-blue light filter to keep perovskite from the UV damage. The tandem device maintains higher performance, particularly during the long term tests. Specifically, Voc of the tandem device achieved a high value of 93% the sum of the component-cells under AM 1.5 illumination. The stability of perovskite solar cells is significantly enhanced comparing with bare perovskite devices. Our results indicate a novel feasible route to elevate the stability of perovskite solar cell without compromising its performance.