Physical Chemistry Division, Department of Chemistry - Angstrom Laboratory, Uppsala University, Box 523, 751 20Uppsala, Sweden.
Departments of Physics and Chemistry and Energy Sciences Institute, Yale University, 217 Prospect Street, P.O. Box 208120, New Haven, Connecticut06520-8120, United States.
J Phys Chem Lett. 2023 Feb 2;14(4):1007-1013. doi: 10.1021/acs.jpclett.2c03720. Epub 2023 Jan 24.
There is an urgent need for efficient solution-processable p-type semiconductors. Copper(I) iodide (CuI) has attracted attention as a potential candidate due to its good electrical properties and ease of preparation. However, its carrier dynamics still need to be better understood. Carrier dynamics after bandgap excitation yielded a convoluted signal of free carriers (positive signal) and a negative feature, which was also present when the material was excited with sub-bandgap excitation energies. This previously unseen feature was found to be dependent on measurement temperature and attributed to negative photoconductivity. The unexpected signal relates to the formation of polarons or strongly bound excitons. The possibility of coupling CuI to plasmonic sensitizers is also tested, yielding positive results. The outcomes mentioned above could have profound implications regarding the applicability of CuI in photocatalytic and photovoltaic systems and could also open a whole new range of possible applications.
目前迫切需要高效的溶液处理型 p 型半导体。碘化亚铜 (CuI) 因其良好的电学性能和易于制备而引起了人们的关注。然而，其载流子动力学仍需要更好地理解。带隙激发后的载流子动力学产生了自由载流子的复杂信号（正信号）和一个负特征，当材料用亚带隙激发能激发时也会出现这个负特征。这个以前未见过的特征被发现与负光导性有关。这个出乎意料的信号与极化子或强束缚激子的形成有关。还测试了 CuI 与等离子体敏化剂的耦合可能性，结果是积极的。上述结果对于 CuI 在光催化和光伏系统中的适用性可能具有深远的意义，也可能开辟全新的应用范围。
