Heterojunction Incorporating Perovskite and Microporous Metal–Organic Framework Nanocrystals for Efficient and Stable Solar Cells

In this paper, we present a facile approach to enhance the efficiency and stability of perovskite solar cells (PSCs) by incorporating perovskite with microporous indium-based metal–organic framework [In 12 O(OH) 16 (H 2 O) 5 (btc) 6 ] n (In-BTC) nanocrystals and forming heterojunction light-harvesting layer. The interconnected micropores and terminal oxygen sites of In-BTC allow the preferential crystallization of perovskite inside the regular cavities, endowing the derived films with improved morphology/crystallinity and reduced grain boundaries/defects. Consequently, the In-BTC-modified PSC yields enhanced fill factor of 0.79 and power conversion efficiency (PCE) of 20.87%, surpassing the pristine device (0.76 and 19.52%, respectively). More importantly, over 80% of the original PCE is retained after 12 days of exposure to ambient environment (25 °C and relative humidity of ~ 65%) without encapsulation, while only about 35% is left to the pristine device.