Implications of the size variation on the local structure and polarized emission of CsPbBr.sub.3 quantum dots

• Published in: Journal of materials science Vol. 56; no. 11; pp. 6977 - 6986
• Main Authors: Shinde, Aparna, Gahlaut, Richa, Abharana, N, Bhattacharyya, Dibyendu, Mahamuni, Shailaja
• Format: Journal Article
• Language: English
• Published: Springer 03.01.2021
• Subjects: Perovskite; Photoluminescence
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-020-05712-1

CsPbBr.sub.3 nanocrystals (NCs) due to their extraordinary photoluminescence quantum yield and photostability without any inorganic passivation (core-shell) are probable candidates for LED and LASER applications. Additionally, the polarized luminescence of these NCs in ensemble broadens the field of applications, especially in liquid crystal display. Here, we report structural distortions and polarized emission from CsPbBr.sub.3 nanocubes with varying sizes of NCs. The change in Br-Pb and Br-Cs bond lengths with decreasing size of QDs reveals secrete of unprecedented increase in degree of emission polarization. The observed degree of polarization in this study is the highest reported value so far for lead halide perovskite structures in ensemble form without any additional alignment process. Different experimental configurations are used to study the transition dipole moments of CsPbBr.sub.3 NCs, which suggests that the transition dipole moments of absorption and emission are non collinear.