Enhanced Photoluminescence Quantum Yield, Lifetime, and Photodetector Responsivity of CsPbBr<sub>3</sub> Quantum Dots via Antimony Tribromide Post-Treatment
Mohan Raj Subramaniam, Ashna K. Pramod, Samuel A. Hevia, Sudip K. Batabyal
Abstract
Herein, we present the synthesis of CsPbBr3 quantum dots (QDs) by a ligand-assisted reprecipitation (LARP) technique under an ambient atmosphere. Besides, the optoelectronic properties of CsPbBr3 QDs were improved through antimony tribromide (SbBr3) post-treatment. Photoluminescence quantum yield (PLQY) was enhanced from 72 to 89% for SbBr3 post-treated QDs compared to as-synthesized QDs. High-resolution transmission electron microscopy (HR-TEM) analysis shows the formation of uniform-size CsPbBr3 QDs (9.4 ± 1.3 nm) after SbBr3 treatment. The X-ray diffraction (XRD) pattern confirms the presence of the cubic phase of CsPbBr3 QDs before and post-treatment. Moreover, temperature-dependent PL and X-ray photoelectron spectroscopy (XPS) characterizations confirm the effective defect passivation with SbBr3 post-treatment. The time-resolved PL lifetime of CsPbBr3 QDs was enhanced from 24.80 ± 0.10 to 37.71 ± 0.09 ns after post-treatment. Finally, the post-treated QD-based self-powered photodetector device showed a high responsivity of 48.1 μA/W compared to the as-synthesized QD device’s responsivity of 10.2 μA/W.