Spectroscopic Investigation of Structural Perturbations in CsPbCl₃ Perovskite Nanocrystals: Temperature- and Excitation-Energy-Dependent Study

Abstract

Inorganic lead halide perovskites are at the frontier of photovoltaic research due to their groundbreaking performance as an absorbing layer in solar cells. Cesium lead chloride (CsPbCl3), known to be a competent material for its blue emission, undergoes subsequent temperature-dependent phase transitions. The photophysical aspects reliant on temperature as well as the phase exhibited by the material are still unknown. Herein, we have studied the temperature- and excitation-energy-dependent underlying photophysics in CsPbCl3 nanocrystals (NCs) employing ultrafast transient absorption (TA) and terahertz (THz) spectroscopy. The direct dependence of carrier relaxation, carrier temperature, and energy loss on the phase transition has been established. Also, to comprehend the outcome of excitation energy, photoconductivity and mobility were determined with the help of optical pump THz probe spectroscopy, and it is established that as the excitation energy is reduced, mobility decay is found to be slow due to diminishing Auger recombination and augmented penetration depth.

Efficient open-air synthesis of Mg2+-doped CsPbI3 nanocrystals for high-performance red LEDs

“…δ-CsPbI 3 ), tetragonal (β-CsPbI 3 ), and orthorhombic (γ-CsPbI 3 ) structures. 5 Typically, cubic CsPbI 3 exhibits a narrow direct band gap of approximately 1.73 eV, 6 which is the smallest value compared to those of CsPbCl 3 (∼3 eV) 7 and CsPbBr 3 (∼2.3 eV). 8 The unique bandgap of α-CsPbI 3 NCs makes them highly suitable for applications in light emitting diodes (LEDs) 9 and solar cells.…”

Hot Carrier Temperature Dynamics in Semiconductor Nanostructures: Full Lineshape Modeling of Ultrafast Time-Resolved Emission Spectra

“…Transient spectroscopies, utilizing absorption ,,− and emission, − are currently employed to delve into the intricate dynamics of carrier cooling. Transient absorption spectra, especially when modeling the high-energy tail, offer insights into carrier temperatures and their temporal evolution. , Nonetheless, the efficacy of this method is contingent upon the careful selection of the spectral range for modeling, which introduces a degree of subjectivity .…”