Effects of Repetitive Pressure on the Photoluminescence of Bare and ZnS-Capped CuInS2 Quantum Dots: Implications for Nanoscale Stress Sensors

作者：Wang, Jundiao; Ning, Haoran; Wang, Jun; Kershaw, Stephen, V; Jing, Lihong^*; Xiao, Pan^*

来源：ACS Applied Nano Materials, 2022, 5(4): 5617-5624.

DOI：10.1021/acsanm.2c00573

• CuInS2 quantum dots
• core
• shell structure
• repetitive loading
• stress
• strain sensing
• photoluminescence properties

Semiconductor quantum dots (QDs) are promising materials for stress/strain sensing applications owing to their pressure-dependent photoluminescence (PL) and nanoscale size, while the impact of stress and microstructure on their optical properties still awaits in-depth investigations under more realistic loading conditions. Herein, bare CuInS2 QDs and core- shell structured CuInS2/ZnS QDs are investigated under repetitive pressure loadings to elucidate the pressure-dependent PL responses over many pressure cycles. The CuInS2/ZnS QDs not only show higher PL intensity but also exhibit a reliable and simple relationship between PL emission peak energy (E-PL) and external pressure (P), which is desirable for actual application in stress/strain sensing. Specifically, the E-PL-P relationship of bare CuInS2 QDs changes after the first loading-unloading cycle, while the EPL-P relationship of CuInS2/ZnS QDs shows repeatable trajectories under different cycles. This research provides experimental support for designing QD-based stress/ strain sensing materials and explains how the shell and surface microstructure will affect the mechanical-luminescence responses of

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  中国科学院研究生院