Document Type

Thesis

Date of Award

Spring 4-23-2025

Keywords

Quantum Dots, Shell, Perovskite, Photoluminescence, CsPbBr3, PbS, Stability, Passivation, PLQY

Degree Name

Chemistry (BA, BS)

Department

CHEMISTRY

First Advisor

Dr. Yiliang Luan

Second Advisor

Dr. Nikolay Dimitrov

Series

Science and Mathematics

Abstract

Halide perovskite quantum dots (HPQDs) have attracted considerable attention for optoelectronic applications due to their outstanding optical properties, including high photoluminescent quantum yield (PLQY), tunable band gap, high absorption coefficients, etc. However, their practical implementation is limited by poor stability under ambient conditions such as moisture, heat, and light. To overcome these challenges, surface passivation and shelling engineering have emerged as effective strategies to enhance HPQD stability by encapsulating their surface with a protective material. Conventional shelling techniques, however, often face limitations related to lattice mismatch and interfacial incompatibility. In this study, we report the successful synthesis of PbS@CsPbBr3 (shell@core) QDs via an in situ shelling process employing an activated sulfur precursor. This approach enables low-temperature shell growth which mitigates the thermal degradation of the CsPbBr3 QDs core. The resulting PbS@CsPbBr3 QDs exhibit enhanced PLQY and stability, while retaining their intrinsic spectral properties. Additionally, we systematically examined the influence of shelling stoichiometry and temperature on the structural and optical properties of the PbS@CsPbBr3 QDs. This work not only presents a robust strategy for stabilizing HPQDs but also offers valuable insights into the rational design of surface passivation methods.

Download

Included in

Chemistry Commons

Share

COinS