In-Situ and Reversible Enhancement of Photoluminescence from CsPbBr_3 Nanoplatelets by Electrical Bias

摘要

In-situ and real-time modulation of the optical properties of semiconductor nanoemitters by a CMOS-compatible strategy holds great promise for developing functional and integrated optoelectronic devices. Herein, the reversible and giant (13 times) enhancement of the photoluminescence (PL) from inorganic halide perovskite nanoplatelets by electrical bias is demonstrated for the first time. Based on the comprehensive spectroscopic analysis, the improved PL performance is attributed to the dynamic surface healing effect by bias-induced ion redistribution. The switching from PL quenching to PL enhancement from CsPbBr3 nanoplatelet is manifested at threshold temperature of approximate to 190 K. Moreover, the temperature dependent measurements unravel the activation energy of 142.8 +/- 31.1 meV, corroborating that the drifted species of anion (Br-) or V-Br dominates the trap healing process. Accordingly, a three-stage defect passivation model of the vertical configuration is established. The synergistic effects of ion redistribution and charge injection caused by thermal equilibrium energy band bending on the optical properties of the perovskite is further investigated by contacting the perovskite with indium tin oxide electrode. These results provide novel insight into the photophysical properties of halide perovskites and are beneficial for display and lighting applications in future, especially on-chip integrated photonics circuits and systems.