The Effect of Post-Baking Temperature and Thickness of ZnO Electron Transport Layers for Efficient Planar Heterojunction Organometal-Trihalide Perovskite Solar Cells

• Main Authors: Kun-Mu Lee, Chuan-Jung Lin, Yin-Hsuan Chang, Ting-Han Lin, Vembu Suryanarayanan, Ming-Chung Wu
• Format: Article
• Language: English
• Published: MDPI AG 2017-11-01
• Series: Coatings
• Subjects: zinc oxide; perovskite; photovoltaic; electron transport layer
• Online Access: https://www.mdpi.com/2079-6412/7/12/215

Solution-processed zinc oxide (ZnO)-based planar heterojunction perovskite photovoltaic device is reported in this study. The photovoltaic device benefits from the ZnO film as a high-conductivity and high-transparent electron transport layer. The optimal electron transport layer thickness and post-baking temperature for ZnO are systematically studied by scanning electron microscopy, photoluminescence and time-resolved photoluminescence spectroscopy, and X-ray diffraction. Optimized perovskite solar cells (PSCs) show an open-circuit voltage, a short-circuit current density, and a fill factor of 1.04 V, 18.71 mA/cm2, and 70.2%, respectively. The highest power conversion efficiency of 13.66% was obtained when the device was prepared with a ZnO electron transport layer with a thickness of ~20 nm and when post-baking at 180 °C for 30 min. Finally, the stability of the highest performance ZnO-based PSCs without encapsulation was investigated in detail.