NiO@ZnO composite bimetallic nanocrystalline decorated TiO2-CsPbI3 photo-anode surface modifications for perovskite-sensitized solar cell applications

Abstract

In this work, we fabricated a novel NiO@ZnO modification of TiO2-CsPbI3 photoanode-based Perovskite solar cells (PSCs). A facile hydrothermal synthesis is adopted for the preparation of NiO@ZnO-modified TiO2-CsPbI3 composite. The as-prepared NiO@ZnO modified TiO2-CsPbI3 composite is characterized by XRD, HR-TEM, SAED, FE-SEM with EDAX, AFM, XPS, FT-IR, UV-Vis, and Tauc plot analysis. UV-Vis spectra show that visible light absorption of the NiO@ZnO modified TiO2-CsPbI3 bilayer photoanode was more effective than NiO/ZnO modified TiO2-CsPbI3. XRD analysis showed the formation of NiO@ZnO in the TiO2-CsPbI3 in cubic crystalline nature. Morphological analyses were performed using FESEM, HRTEM, SAED, and AFM which revealed the formation of NiO@ZnO-modified TiO2-CsPbI3 with a multi-crystalline surface. EDAX and XPS analyses confirmed the presence of Ni, Zn, O, Ti, Cs, Pb, and I elements in the NiO@ZnO-modified TiO2-CsPbI3 composite. FT-IR spectra of perovskite metal oxide and hydroxide stretching vibrations peaks appeared at 920 and 3450 cm−1. The band gap was found to be 2.47 eV for NiO@ZnO-modified TiO2-CsPbI3 by using a Tauc plot. Finally, the photoanode-based PSCs were optimized by adding NiO@ZnO and TiO2-CsPbI3 composite, giving a high efficiency of 8.73%. We confirm that NiO@ZnO-modified TiO2-CsPbI3 bilayer photoanode-based PSCs show a better performance than NiO and ZnO-modified TiO2-CsPbI3.