Facile Synthesis of Spherical TiO2 Hollow Nanospheres with a Diameter of 150 nm for High-Performance Mesoporous Perovskite Solar Cells

Abstract

The electron transport layer (ETL) of organic–inorganic perovskite solar cells plays an important role in their power conversion efficiency (PCE). In this study, TiO2 hollow nanospheres with a diameter of 150 nm were prepared by a facile synthesis method. The synthesized TiO2 hollow nanospheres had a highly porous structure with a surface area of 85.23 m2 g−1, which is significantly higher than commercial TiO2 (P25) (54.32 m2 g−1), indicating that they can form an ideal mesoporous layer for Formamidinium iodide-based perovskite solar cells (PSCs). In addition, the nanospheres achieved a remarkable perovskite performance, and the average PCE increased from 12.87% to 14.27% with a short circuit current density of 22.36 mAcm−2, an open voltage of 0.95 V, and a fill factor of 0.65. The scanning electron microscopy images revealed that the enhanced PCE could be due to the improved carrier collection and transport properties of the nanosphere, which enabled efficient filtration of perovskite into the TiO2 mesoporous ETL. The TiO2 hollow nanospheres fabricated in this study show high potential as a high-quality ETL material for efficient (FAPbI3)0.97(MAPbBr3)0.03-based PSCs.

Reduced Defects and Enhanced Performance of (FAPbI3)0.97(MAPbBr3)0.03-Based Perovskite Solar Cells by Trimesic Acid Additives

“…The quality of perovskite films, which can be influenced by the preparation method, makes a significant contribution to the device capacity of PSCs. − However, owing to the difficulties in controlling these perovskite films including their organic components, rough and inhomogeneous films, which are sensitive to air, are formed. − The modification of the perovskite surface by enhancing the crystallinity, suppressing the surface defects, and reducing the number of pinholes has emerged as a powerful method to improve the film quality of perovskites. In the previous research, our group modified the perovskite surface by inserting an ultrathin NiO@C interfacial layer on the top of the perovskite layer, achieving a high efficiency of 15.78% in the planar n–i–p structure. , …”

Porous Electrospun Carbon Nanofibers Bearing TiO2 Hollow Nanospheres for Supercapacitor Electrodes

“…Nonetheless, it is important to note that the S BET values may not accurately represent the absolute characteristics of the prepared samples (excluding hTiO 2 ). This discrepancy can be attributed to substantial differences in densities (TiO 2 (3.78–4.23 g cm –3 ) and CNFs (1.99 g cm –3 )) as well as variations in native S BET values (hTiO 2 (85.23 m 2 g –1 ) and CNF-Bare (568 m 2 g –1 )). When not accounting for the contribution of hTiO 2 mass, the S BET values of the prepared samples (excluding hTiO 2 ) might surpass that of CNF-Bare.…”

Ni-Doped SnO2 as an Electron Transport Layer by a Low-Temperature Process in Planar Perovskite Solar Cells

“…Recently, numerous materials, such as TiO 2 , SnO 2 , ZnO, Zn 2 SnO 4 , WO 3 , etc., have been reported as ETLs. Among them, SnO 2 can be used at low temperature (∼150 °C) and has exhibited better optical and electrical properties, band ailment to perovskite, and stability than the other materials, making it a strong candidate for highly efficient PSCs. − …”