RESUMEN
Coevaporation of perovskite films allows for a fine control over the material stoichiometry and thickness but is typically slow, leading to several-hour processes to obtain thick films required for photovoltaic applications. In this work, we demonstrate the coevaporation of perovskite layers using faster deposition rates, obtaining 1 µm thick films in approximately 50 min. We observed distinct structural properties and obtained devices with efficiency exceeding 19%, demonstrating the relevance of this deposition process from a material perspective and also in view of potential industrialization.
RESUMEN
Improved stability and efficiency of two-terminal monolithic perovskite-silicon tandem solar cells will require reductions in recombination losses. By combining a triple-halide perovskite (1.68 electron volt bandgap) with a piperazinium iodide interfacial modification, we improved the band alignment, reduced nonradiative recombination losses, and enhanced charge extraction at the electron-selective contact. Solar cells showed open-circuit voltages of up to 1.28 volts in p-i-n single junctions and 2.00 volts in perovskite-silicon tandem solar cells. The tandem cells achieve certified power conversion efficiencies of up to 32.5%.
