Carbon-based all-inorganic perovskite solar cells (C-PSCs) are known for their inexpensive manufacturing process. However, their perovskite constituents are susceptible to the formation of numerous structural defects and halide vacancies, which can induce substantial energy level misalignments between the light-absorbing layer and the carbon electrode. This discrepancy hinders the extraction and transfer of holes, thereby adversely affecting the overall efficiency of the device.
Image credit: Chemical Engineering Journal
Researchers from China's Huaqiao University have proposed an interfacial post-treatment strategy aimed at reinforcing perovskite layers through the application of Neostigmine bromide (NMB) as a modifier. The team employed NMB to treat the upper interface of the perovskite, addressing intrinsic phase segregation, passivating surface defects, and filling halogen vacancies, thereby enhancing the photoelectric performance and stability of the device.
The use of NMB effectively promoted the recrystallization of intrinsic phase segregation on the surface of CsPbI2Br film and enhanced the crystal integrity of perovskite surface.
Furthermore, bromine ions (Br−) can occupy halide vacancies. Incorporating NMB at the interface significantly reduces the surface defect concentration of the perovskite layer and optimizes the energy level alignment with the carbon electrode.
Experimental results demonstrated that the device efficiency after NMB treatment reached 14.15%. Even after 30 days of aging at room temperature and a relative humidity of 15% to 20%, the device retained 93% of its initial efficiency.
This research lays the foundation for the development of cost-effective, high-performance, and durable all-inorganic perovskite solar cells.
