High-performance carbon-based CsPbI2Br perovskite solar cells via small molecule modification

All-inorganic CsPbI2Br perovskite material has attracted enormous attention for high-performance photovoltaics due to its excellent thermal stability and suitable bandgap. Furthermore, carbon-based CsPbI2Br perovskite solar cells (C-PSCs) not only further improve the thermal and moisture stability of the devices but also reduce production costs and simplify procedure processes. However, the usage of carbon electrodes introduces new problems, such as poor interface contact and energy level mismatch. Herein, the N-phenylthiourea (PTU) with S atom and N-phenylurea (PU) with O atom are applied for interface modification materials in C-PSCs. The atoms S and O can combine with Pb and enhance perovskite crystallinity as well as manage the energy level. Meanwhile, after passivation of PTU and PU, the defect state density of the perovskite layer is significantly reduced, thereby inhibiting the recombination of carriers. The Voc of the device with PTU increases from 1.12 V to 1.22 V, 9% improvement over the control device. The efficiency of CsPbI2Br C-PSCs is improved from 10.29% to 13.01% after modification. Furthermore, the stability of the device has been improved. This study provides a strategy for developing highly efficient and stable C-PSCs.

Automated summary

The study successfully improved the efficiency and stability of CsPbI2Br perovskite C-PSCs using interface modification materials with sulfur and oxygen atoms, providing a new strategy for developing highly efficient and stable C-PSCs.