Liu Diwen, Zha Wenying, Yuan Rusheng, Lou Benyong, Sa Rongjian
Institute of Oceanography, Fujian Key Laboratory of Functional Marine Sensing Materials, Minjiang University Fuzhou Fujian 350108 China
College of Materials and Chemical Engineering, Pingxiang University Pingxiang 337055 China.
RSC Adv. 2020 Oct 6;10(60):36734-36740. doi: 10.1039/d0ra07586h. eCollection 2020 Oct 1.
In recent years, double perovskites have attracted considerable attention as potential candidates for photovoltaic applications. However, most double perovskites are not suitable for single-junction solar cells due to their large band gaps (over 2.0 eV). In the present study, we have investigated the structural, mechanical, electronic and optical properties of the CsTe Ti I solid solutions using first-principles calculations based on density functional theory. These compounds exhibit good structural stability compared to CHNHPbI. The results suggest that CsTeI is an indirect band gap semiconductor, and it can become a direct band gap semiconductor with the value of 1.09 eV when the doping concentration of Ti is 0.50. Moreover, an ideal direct band gap of 1.31 eV is obtained for CsTeTiI. The calculated results indicate that all the structures are ductile materials except for CsTeTiI. Our results also show that these materials possess large absorption coefficients in the visible light region. Our work can provide a route to explore stable, environmentally friendly and high-efficiency light absorbers for use in optoelectronic applications.
近年来，双钙钛矿作为光伏应用的潜在候选材料受到了广泛关注。然而，由于大多数双钙钛矿的带隙较大（超过2.0 eV），它们并不适合用于单结太阳能电池。在本研究中，我们基于密度泛函理论，采用第一性原理计算方法，研究了CsTeTiI固溶体的结构、力学、电子和光学性质。与CHNHPbI相比，这些化合物表现出良好的结构稳定性。结果表明，CsTeI是一种间接带隙半导体，当Ti的掺杂浓度为0.50时，它可以成为直接带隙半导体，其值为1.09 eV。此外，CsTeTiI的理想直接带隙为1.31 eV。计算结果表明，除CsTeTiI外，所有结构均为韧性材料。我们的结果还表明，这些材料在可见光区域具有较大的吸收系数。我们的工作可以为探索用于光电子应用的稳定、环境友好且高效的光吸收剂提供一条途径。
