Automated Scalable Spray Coating of SnO2 for the Fabrication of Low-Temperature Perovskite Solar Cells and Modules

In the renewable energy field, the use of hybrid perovskite materials has opened up new directions to fabricate cost-effective and highly efficient photovoltaic devices. Despite impressive power conversion efficiency (PCE), exceeding 25.2%, demonstrated on lab-scale devices, scalability and stability of device are still topical issues. In this context, large-area deposition procedures and automated fabrication protocols are required to achieve high throughput serial production of modules and panels. In this work, a spray-coated tin oxide (SnO2) layer processed at low temperature for the realization of planar perovskite solar cells (PSCs) and modules is demonstrated. Using sprayed Np-SnO2 as the electron transport layer (ETL), a CH3NH3PbI3-based solar device shows a maximum PCE of 16.77% (avg. 15.01%) comparable to 17% (avg. 15.5%) with respect to spin-coated Np-SnO2. Unencapsulated spray- and spin-coated PSCs stored in 25 degrees C and 50% relative humidity show shelf life stability by retaining 85% of the initial PCE value after more than 1000 h. Moreover, the feasibility of fabrication of the modules with 15 cm(2) active area is demonstrated, which reaches 9.37% of PCE from uniform spray-deposited SnO2 film on a large area (20 x 20 cm(2)).