Solar cells made up of lead-halide perovskites have shown a remarkable increase in power conversion efficiency; however, they are plagued with instability issues that combined with the toxicity of lead have led to a search for new semiconductors made up of heavy and non-toxic metals such as bismuth. Here, we report on a new, inorganic, double perovskite oxide semiconductor: KBaTeBiO6, which has an experimental indirect band gap of 1.5 eV and shows excellent stability. We combined data analytics and high throughput density-functional-theory calculations to search through thousands of hypothetical inorganic double perovskite oxides containing bismuth and predict KBaTeBiO6 as a promising photovoltaic material, which was subsequently synthesized using a wet-chemistry route. The calculated effective mass of the charge carriers and the spectroscopic limited maximum efficiency for KBaTeBiO6 is comparable to the best performing Bi-halide double perovskites. We have fabricated photoelectrochemical solar cells with KBaTeBiO6 nanoparticles as the active absorber layer, which show promising performance. Our work demonstrates the untapped potential of inorganic Bi-based double perovskite oxides—that offer the ability to change both the cation combination and their stoichiometry to achieve desired electronic properties—as exciting, benign and stable alternatives to lead-halide perovskites for various semiconducting applications.

KBaTeBiO<sub>6</sub>: Lead-free, inorganic double-perovskite semiconductor for photovoltaic applications

2019 Fall National Meeting

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KBaTeBiO6: Lead-free, inorganic double-perovskite semiconductor for photovoltaic applications

KBaTeBiO₆: Lead-free, inorganic double-perovskite semiconductor for photovoltaic applications