Eshete Mesfin, Li Xiyu, Xie Tian, Jiang Jun, Zhang Guozhen
Hefei National Laboratory for Physical Sciences at the Microscale, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), School of Chemistry and Materials Science , University of Science and Technology of China , Hefei , Anhui 230026 , China.
State Key Laboratory of Efficient Utilization for Low Grade Phosphate Rock and Its Associated Resources , Wengfu Group , Guiyang 550014 , China.
J Phys Chem Lett. 2019 Aug 1;10(15):4317-4322. doi: 10.1021/acs.jpclett.9b01436. Epub 2019 Jul 18.
Hybrid heterostructures are a promising type of materials framework for optoelectronic conversion. We designed a ternary energy-dependent thin layer of CuS-Pt-WO (p-type-metal-n-type) heterojunction to explore an alternative way of realizing efficient charge separation. First-principles calculations showed that the Fermi level of the whole system is lined up via the mediation of Pt metal, which fosters the combination of holes in CuS and electrons in WO and keeps electrons in CuS and holes in WO well separated. Importantly, creation of band bending and charge polarization steer low-energy charges selectively to the intermediate metal and keep high-energy charges on individual semiconductors apart. Our simulation analysis of two-dimensional layers with the metal bridge shows increased charge flows across the junction compared to that of their bulk counterparts. Overall, this heterojunction is viable for suppressing recombination of photogenerated electron-hole pairs and augmented electrons per surface that would allow enhanced optoelectronic conversion.
混合异质结构是一种很有前途的用于光电转换的材料框架类型。我们设计了一种三元能量依赖型的CuS-Pt-WO（p型-金属-n型）异质结薄层，以探索实现高效电荷分离的替代方法。第一性原理计算表明，整个系统的费米能级通过Pt金属的介导排列，这促进了CuS中的空穴与WO中的电子的结合，并使CuS中的电子和WO中的空穴保持良好分离。重要的是，能带弯曲和电荷极化的产生将低能电荷选择性地导向中间金属，并使高能电荷在单个半导体上分开。我们对带有金属桥的二维层的模拟分析表明，与体相材料相比，结处的电荷流动增加。总体而言，这种异质结对于抑制光生电子-空穴对的复合以及增加每表面的电子数量是可行的，这将有助于增强光电转换。
