Structural effects on the luminescence properties of CsPbI₃ nanocrystals

Abstract

Metal halide perovskite nanocrystals (NCs) are promising for photovoltaic and light emitting applications. Due to the softness of their crystal lattice, structural modifications have a critical impact on their optoelectronic...

Assessing the Optoelectronic Performance of Halide Perovskite Quantum Dots with Identical Bandgaps: Composition Tuning Versus Quantum Confinement

“…Our results disclose that CsPbI 2.5 Br 0.5 and CsPbI 3 QDs demonstrated different behaviors under pressure. Notably, the pressure-induced PL peaks are reversible, suggesting that both QDs did not degrade during pressure measurements though the PL intensities decreased in both QDs upon the pressure release (see Figure S4), which aligns with previous reports. − …”

“…The size of QDs is known to play a critical role in determining the phase transition pressure. Typically, smaller-size halide perovskite QDs exhibit lower transition pressures due to their shorter fluctuation length scales and stronger surface fluctuations. , However, in our case, we observed that the transition pressure of CsPbI 3 QDs (2.5 GPa) is unexpectedly larger than that of CsPbI 2.5 Br 0.5 QDs (1.3 GPa), despite the smaller size of CsPbI 3 (9.7 nm) QDs compared to CsPbI 2.5 Br 0.5 QDs (12.6 nm). Previous studies have also reported a transition pressure from the crystalline to amorphous state of CsPbBr 3 QDs at 2.09 GPa .…”

Temperature-dependent excited states for detecting reversible phase transitions in 2D lead(ii) iodide perovskites

“…There are several reports on the excited-states, photoluminescence quantum yields, and responsiveness to external stimuli. For example for APbX 3 perovskites; A = Cs + , CH 3 NH 3 + , or NH 2 CHNH 2 + [30][31][32][33] and 2D perovskites such as (C 4 H 9 NH 3 ) 2 PbI 4 , (BDA)PbBr 4 . [34][35][36] However, the current study aims to show how photophysical properties change as a function of temperature across phases transitions which have not been thoroughly investigated and warrant further study.…”