A strategy toward air-stable and high-performance ZnO-based perovskite solar cells fabricated under ambient conditions

Despite the recently reported efficiency over 20%, the long-term stability of perovskite solar cells (PSCs) under ambient conditions remains a great challenge. For most of the highly efficient PSCs, fabrication processes are usually carried out in glovebox to guarantee their performance and stability. Herein, a new manufacturing strategy is introduced to optimize the device performance under ambient conditions. We skillfully merge both of ultrasonic assisted method and a two-step sequential spin-coating deposition technique to prepare a more compact and pinhole-free ZnO and perovskite films in air. As a result, the ZnO-based PSC with a conventional structure of glass/FTO/ZnO/CH 3 NH 3 PbI 3 /Spiro-OMeTAD/Au demonstrate an efficiency of up to 14.25%. Notably, the efficiency can be maintained at 86.25% of its initial value even though it is exposed to air for 45 days. Most importantly, all processes including fabrication, measurement as well as storage are performed in ambient air. We believe the proposed synergetic strategy can open up a new pathway for boosting the commercial applications of PSCs.