UC Irvine

Commercialization of solar cells based on photoactive lead halide perovskites is in part limited by their toxicity and instability. In this study, new and related copper halide hybrid organic-inorganic materials containing dicationic hexane-1,6-diammonium (+H3N-C6H12-NH3+) demonstrated superior stability to heat and moisture in comparison to the analogous material containing monocationic n-propylammonium (C3H7-NH3+) in twice the stoichiometry. Electronic absorption spectra taken of the materials were consistent with an indirect optical bandgap of ∼1.8 eV, making them well-suited for application as the photoactive layer in the top cell of a tandem solar cell with silicon. The best-performing single-junction solar cells containing the dicationic material as the photoactive layer exhibited an open-circuit photovoltage in excess of 400 mV and a short-circuit photocurrent density of ∼30 μA/cm2. These values are similar to those reported for state-of-the-art copper halide hybrid organic-inorganic materials containing organic monocations and motivate further research on this class of materials.