Improving perovskite solar cells with laminated carbon paper electrodes by copper-doped indium hydroxide nanoparticles

Carbon electrodes offer significant advantages for the industrialization of perovskite solar cells, including chemical stability, printability, low cost, and prevention of lead leakage. The lamination method enables low-temperature assembly of carbon electrodes while avoiding damage to the perovskite absorber layer caused by solvents in carbon pastes. However, the efficiency of laminated devices is critically dependent on the quality of interfacial contact and energy level alignment at the carbon electrode interface. Herein, copper-doped indium hydroxide nanoparticles were synthesized via a hydrothermal method to modify the interface of carbon electrodes. Different from the development of functional carbon materials in previous reports, the interfacial modification method improves the contact and the energy level alignment between conventional carbon electrodes and hole transport layers. Consequently, the modification layer promotes interfacial charge transport and enhances the built-in electric field within the device, thereby reducing recombination processes and improving charge collection efficiency. As a result, the power conversion efficiency of the carbon-based devices increases from 17.24% to 18.58%, accompanied by enhanced device stability. This work demonstrates a strategy for improving conventional carbon electrodes by interfacial modification with inorganic nanoparticles, paving the way for the commercialization of carbon-based perovskite solar cells.