Hamanaka Yasushi, Okuyama Satoshi, Yokoi Rin, Kuzuya Toshihiro, Takeda Keiki, Sekine Chihiro
Department of Physical Science and Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, 466-8555, Japan.
College of Design and Manufacturing Technology, Muroran Institute of Technology, Mizumoto-cho, Muroran, 050-8585, Japan.
Chemphyschem. 2023 Nov 2;24(21):e202300029. doi: 10.1002/cphc.202300029. Epub 2023 Aug 23.
High-density assemblies or superlattice structures composed of colloidal semiconductor nanocrystals have attracted attention as key materials for next-generation photoelectric conversion devices such as quantum-dot solar cells. In these nanocrystal solids, unique transport and optical phenomena occur due to quantum coupling of localized energy states, charge-carrier hopping, and electromagnetic interactions among closely arranged nanocrystals. In particular, the photoexcited carrier dynamics in nanocrystal solids is important because it significantly affects various device parameters. In this study, we report the photoexcited carrier dynamics in a solid film of CuInS nanocrystals, which is one of the potential nontoxic substitutes with Cd- and Pb-free compositions. Meanwhile, these subjects have been extensively studied in nanocrystal solids formed by CdSe and PbS systems. A carrier-hopping mechanism was confirmed using temperature-dependent photoluminescence spectroscopy, which yielded a typical value of the photoexcited carrier-transfer rate of (2.2±0.6)×10 s by suppressing the influence of the excitation-energy transfer.
由胶体半导体纳米晶体组成的高密度组件或超晶格结构，作为量子点太阳能电池等下一代光电转换器件的关键材料受到了关注。在这些纳米晶体固体中，由于局域能态的量子耦合、电荷载流子跳跃以及紧密排列的纳米晶体之间的电磁相互作用，会出现独特的输运和光学现象。特别是，纳米晶体固体中的光激发载流子动力学很重要，因为它会显著影响各种器件参数。在本研究中，我们报告了CuInS纳米晶体固体薄膜中的光激发载流子动力学，CuInS是一种具有无镉和无铅成分的潜在无毒替代品。同时，这些课题在由CdSe和PbS系统形成的纳米晶体固体中已得到广泛研究。通过抑制激发能量转移的影响，利用温度相关光致发光光谱证实了一种载流子跳跃机制，该机制给出的光激发载流子转移速率的典型值为(2.2±0.6)×10 s 。
