In‐Situ and Reversible Enhancement of Photoluminescence from CsPbBr₃ Nanoplatelets by Electrical Bias

Abstract

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 ≈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 VBr 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.

Remanent Polarization and Strong Photoluminescence Modulation by an External Electric Field in Epitaxial CsPbBr3 Nanowires

“…No apparent change was observed in the band-edge emission and spectral width for DC fields of 10 6 V/m (Figure S2), which is reasonable, as significant Stark shifts typically require stronger fields (∼10 8 V/m) . Ion migration was linked before with PL enhancement in CsPbBr 3 nanocrystals under bias . However, this cannot be the cause for the PL switching in our case, since the asymmetric PL response is irreversible, and the frequency range is higher (Figure b,c and Figure S5a) than the reported response time of ion migration in MHPs …”

“…16 Ion migration was linked before with PL enhancement in CsPbBr 3 nanocrystals under bias. 17 However, this cannot be the cause for the PL switching in our case, since the asymmetric PL response is irreversible, and the frequency range is higher (Figure 2b,c and Figure S5a) than the reported response time of ion migration in MHPs. 18 Large Modulation Depth and Slow Carrier Dynamics under an E-Field.…”

Binding of CsPbBr3 Nanocrystals to MOF-5 for the Detection of Cadmium Ions in Aqueous Media

“…However, the extent of an increase in the lifetime is high compared to an increase in PL, or the difference in F / F 0 and τ/τ 0 is not exactly equal, and this is because of the suppressed PL (20%) due to IFE. Thus, F 0 / F ≈ τ 0 /τ strongly signifies excited-state interaction (electrostatic interaction) between the analyte and probe …”

High-Quality Wave-Chaotic Microlasers from Deformed Halide Perovskite Cavities

“…First, the temperature was set in the range of 530−570 °C that is suitable for 2D growth of CsPbBr 3 perovskite microcrystals. 32,33 Second, to tune the molecular supersaturation, the substrate was placed at three areas (A, B, and C, see Figure 1a) that had different distances to hot-zone center, where the supersaturation increases monotonously from A, B, to C. Third, the substrates of ITO and muscovite mica with largely different E ad were adopted to establish the effect of surface adsorption energy on the crystal growth. Specifically, the ITO shows a cubic bixbyite structure constituted by In 2 O 3 and SnO 2 , the solid solution processes that In 3+ ions are substituted randomly by Sn 4+ generate a bunch of oxygen-dangling bonds on the substrate surface.…”