A bismuth-based (III) hybrid perovskite as a highly air-stable, potential absorber with photoconductive response

Organic-inorganic hybrid perovskites materials (CH3NH3PbI3) are recently great attention in the field of optoelectronic and photovoltaic devices. But, the stability and toxicity issues of the lead have seriously affected its commercial application. Here, we described a novel lead-free hybrid bismuth-based compound, [tert-butylammonium]2 [Bi2I9] (TBI), which adopts a one-dimensional perovskite-like manner containing the corner-sharing BiI6 octahedra structure. TBI displays outstanding light-absorbing properties with a gradual absorption edge at 632 nm, and optical bandgap of ∼1.96 eV which is lower than the bandgap of CH3NH3PbBr3 and its semiconducting properties were steadily confirmed by the positive temperature-dependent conductivity along with the prominent photo-conductive responses in the range of (20 °C) 320–420 K (80 °C). In addition, TBI also shows brilliant phase stability from 1 day to 48 days in the open atmosphere, being much higher than CH3NH3PbI3. This result suggests the potentials of TBI as the excellent absorber for photovoltaic and solar cell applications. [Display omitted] •We succeeded in synthesizing TBI, a novel bismuth-based hybrid perovskite.•With a small optical bandgap of 1.96 eV, TBI exhibits excellent light absorption.•TBI also exhibits substantially better phase stability than that of CH3NH3PbI3 does.•This research opens a new avenue for investigating eco-friendly materials.