Zhang Jing-Yi, Wu Xiao-Bin, Shi Jun-Jie
Opto-electronic Center, Institute of Microelectronics of the Chinese Academy of Sciences, Beijing 100029, China.
School of Integrated Circuits, University of Chinese Academy of Sciences, Beijing 100049, China.
Phys Chem Chem Phys. 2024 Dec 4;26(47):29584-29594. doi: 10.1039/d4cp03335c.
Nowadays, substantial progress has been achieved in developing advanced solar cell materials, including high-performance two-dimensional (2D) materials like chalcogenides, perovskites, and oxides, along with their van der Waals (vdW) heterostructures. These efforts target enhanced photovoltaic efficiency, cost reduction, and reduced environmental impact. Despite this, challenges remain in improving light absorption, carrier mobility, and power conversion efficiency (PCE), highlighting the need for materials with enhanced optoelectronic properties. Here, we build a 2D MoSiAs/MoGeN vdW heterostructure with a 3.39 Å layer spacing, featuring an indirect band gap of 1.14 eV and type-II band alignment. Computational assessments demonstrate that photo-generated electrons efficiently transfer from the MoSiAs to the MoGeN layer, while holes move in the opposite direction, reducing electron-hole recombination. The heterostructure exhibits excellent stability and optical absorption, with absorption coefficients up to 10 cm across an extensive spectral range from visible to ultraviolet light. Furthermore, it also showcases an impressive electron mobility of 9065 cm V s and a minimal conduction band offset of 0.05 eV, both of which contribute to an enhanced PCE, reaching up to 22.09%. These results position the MoSiAs/MoGeN heterostructure as a promising candidate for solar cell applications due to its superior optoelectronic properties.
如今，在开发先进的太阳能电池材料方面已取得了重大进展，包括高性能的二维（2D）材料，如硫族化物、钙钛矿和氧化物，以及它们的范德华（vdW）异质结构。这些努力旨在提高光伏效率、降低成本并减少环境影响。尽管如此，在改善光吸收、载流子迁移率和功率转换效率（PCE）方面仍然存在挑战，这突出了对具有增强光电性能的材料的需求。在此，我们构建了一种层间距为3.39 Å的二维MoSiAs/MoGeN vdW异质结构，其间接带隙为1.14 eV，具有II型能带排列。计算评估表明，光生电子有效地从MoSiAs转移到MoGeN层，而空穴则向相反方向移动，减少了电子 - 空穴复合。该异质结构表现出优异的稳定性和光吸收性能，在从可见光到紫外光的广泛光谱范围内，吸收系数高达10 cm。此外，它还展示了令人印象深刻的9065 cm V s的电子迁移率和0.05 eV的最小导带偏移，这两者都有助于提高PCE，达到22.09%。由于其优异的光电性能，这些结果使MoSiAs/MoGeN异质结构成为太阳能电池应用的有前途的候选材料。
