Intermediate-phase-assisted low-temperature formation of γ-CsPbI₃ films for high-efficiency deep-red light-emitting devices.

ABSTRACT: Black phase CsPbI₃ is attractive for optoelectronic devices, while usually it has a high formation energy and requires an annealing temperature of above 300 °C. The formation energy can be significantly reduced by adding HI in the precursor. However, the resulting films are not suitable for light-emitting applications due to the high trap densities and low photoluminescence quantum efficiencies, and the low temperature formation mechanism is not well understood yet. Here, we demonstrate a general approach for deposition of γ-CsPbI₃ films at 100 °C with high photoluminescence quantum efficiencies by adding organic ammonium cations, and the resulting light-emitting diode exhibits an external quantum efficiency of 10.4% with suppressed efficiency roll-off. We reveal that

SUBMITTER: Yi C 

PROVIDER: S-EPMC7505955 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature