Boosting Perovskite Solar Cell Stability through a Sputtered Mo-Doped Tungsten Oxide (WO<sub><i>x</i></sub>) Electron Transport Layer
Samiya Mahjabin, Md. Mahfuzul Haque, Muhammad Shahriar Bashar, Md. Shahiduzzaman, Mohammad Ismail Hossain, Munkhtuul Gantumur, Mohammad Shah Jamal, Rahim Abdur, M. Shakel, Ghulam Muhammad, Tetsuya Taima, Md. Akhtaruzzaman
Abstract
This study focuses on improving the stability of perovskite solar cells (PSCs) by developing a high-quality electron transport material (ETM). The optoelectronic and morphological properties of the ETM play a significant role in PSC performance. To prepare molybdenum-doped tungsten oxide (WO x:Mo) thin films, RF magnetron sputtering, followed by annealing, was used under vacuum conditions. Various sputter deposition times were used to optimize the thin film, and it was characterized for optical, electrical, structural, and morphological properties. Deposited WO x:Mo thin films demonstrated excellent optoelectronic properties and an average transmittance of 60 to 80%, making them suitable for efficient PSCs. The best WO x:Mo thin film was used to fabricate PSCs, resulting in long-term stability (retained >80% of its initial power output after 1440 h of storage at ambient conditions with a humidity range of 40–50%). The complete device optics were studied using the three-dimensional (3D) finite-difference time-domain (FDTD) method. This study demonstrates, for the first time, the use of RF magnetron-sputtered WO x:Mo ETM for PSCs, providing a new pathway for developing next-generation, highly stable PSCs.