Combining First-Principles Simulations and Combinatorial Synthesis: Effects of Exciton Binding Energy Halide Perovskite-Based Optoelectronic Devices

Halide perovskites (HPs) have garnered significant attention in optoelectronics due to their excellent optoelectronic properties. The performance of HP optoelectronics is affected by the exciton binding energy, which represents the combined energy of electron-hole pairs. Therefore, a method that can comprehensively and rapidly explore and measure changes in exciton binding energy based on HP composition is highly valuable. In this study, we report the effects of HP optoelectronic properties depending on the HP compositions using a combination of first-principles simulations and combinatorial synthesis. The first-principles simulations confirm that an increase in the concentration of halide ions leads to an increased band gap, strengthening the Coulomb interactions. We demonstrate that an increase in the band gap corresponds to a decrease in relative permittivity when fabricating HP thin films with a halide compositional gradient using combinatorial synthesis. Furthermore, we measured the photoelectric conversion efficiency and responsivity of HP-based optoelectronics depending on exciton binding energy, including time-resolved photoluminescence. The results indicate that the dissociation of electron-hole pairs increases with a reduction in exciton binding energy, thereby improving device properties. Thus, this study suggests a high-throughput screening method that combines first-principles simulations and combinatorial synthesis to explore the effects of HP properties on optoelectronics.