Wang Changmeng, Tong Xin, Wang Wenhao, Xu Jing-Yin, Besteiro Lucas V, Channa Ali Imran, Lin Feng, Wu Jiang, Wang Qiang, Govorov Alexander O, Vomiero Alberto, Wang Zhiming M
Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China.
Institut National de la Recherche Scientifique, Centre Énergie, Matériaux et Télécommunications, 1650 Boul. Lionel Boulet, J3X 1S2 Varennes, Québec, Canada.
ACS Appl Mater Interfaces. 2020 Aug 12;12(32):36277-36286. doi: 10.1021/acsami.0c11651. Epub 2020 Jul 31.
Colloidal core/shell heterostructured quantum dots (QDs) possessing quasi-type II band structure have demonstrated effective surface passivation and prolonged exciton lifetime, leading to enhanced charge separation/transfer efficiencies that are promising for photovoltaic device applications. Herein, we synthesized CuInS (CIS)/CdS core/shell heterostructured QDs and manipulated the optoelectronic properties via controlling the CdS shell thickness. The shell-thickness-dependent optical properties indicate the existence of a quasi-type II band structure in such core/shell QDs, which was verified by ultrafast spectroscopy and theoretical simulations. These quasi-type II core/shell QDs having various shell thicknesses are used as light absorbers for the fabrication of solar-driven QDs-based photoelectrochemical (PEC) devices, exhibiting an optimized photocurrent density of ∼6.0 mA/cm and excellent stability under simulated AM 1.5G solar illumination. The results demonstrate that quasi-type II CIS/CdS core/shell heterostructured QDs with tailored optoelectronic properties are promising to realize high-performance QDs-based solar energy conversion devices for the production of solar fuels.
具有准II型能带结构的胶体核/壳异质结构量子点（QDs）已表现出有效的表面钝化和延长的激子寿命，从而提高了电荷分离/转移效率，这对于光伏器件应用很有前景。在此，我们合成了CuInS（CIS）/CdS核/壳异质结构量子点，并通过控制CdS壳层厚度来调控其光电性质。壳层厚度依赖的光学性质表明此类核/壳量子点中存在准II型能带结构，这通过超快光谱和理论模拟得到了验证。这些具有不同壳层厚度的准II型核/壳量子点被用作光吸收剂来制备基于量子点的太阳能驱动光电化学（PEC）器件，在模拟AM 1.5G太阳光照下表现出约6.0 mA/cm的优化光电流密度和优异的稳定性。结果表明，具有定制光电性质的准II型CIS/CdS核/壳异质结构量子点有望实现用于太阳能燃料生产的高性能基于量子点的太阳能转换器件。
