Formation of intermediate band in environmentally stable and wide band gap semiconductor, CuAlS₂, have been studied towards potential, low cost and efficient thin film solar cell material. We investigate the effect of sustainable low-cost dopant (Sn and Fe) in CuAlS₂ film by means of density functional theory within the modified Becke-Johnson approximation for the calculation of electronic and optical properties. Polar film of CuAlS₂ in (0 0 1) direction shows lower band gap than the bulk CuAlS₂ due to the excess Cu and Al atoms. Doping of Sn and Fe in CuAlS₂ form partially filled, isolated intermediate band. Absorption coefficients for Sn and Fe doped films show higher absorption under visible energy region than the pristine bulk and film. Fe and Sn doped films show efficiencies of 34.67 and 35.64%, respectively within spectroscopic limited efficiency. By means of present study, Sn and Fe doping formed intermediate band, improved absorption in visible light and power conversion efficiency. We suggest Sn doped CuAlS₂ as the promising material due to higher effective mass ratio of charge carriers, hence lower rate of recombination, indicates improved performance of CuAlS₂ based thin film solar cell.

已经针对潜在，低成本和高效的薄膜太阳能电池材料研究了在环境稳定的宽带隙半导体CuAlS _2中形成中间带。我们在改进的Becke-Johnson近似中通过密度泛函理论研究了CuAlS ₂薄膜中可持续的低成本掺杂剂（Sn和Fe）的影响，以计算电子和光学性质。由于过量的Cu和Al原子，在（0 0 1）方向上的CuAlS ₂极性膜显示出比体CuAlS ₂更低的带隙。CuAlS ₂中Sn和Fe的掺杂形成部分填充的隔离中间带。掺杂锡和铁的薄膜的吸收系数在可见光能量范围内显示出比原始块和薄膜更高的吸收系数。Fe和Sn掺杂的薄膜在光谱极限效率内分别显示出34.67％和35.64％的效率。通过本研究，Sn和Fe掺杂形成中间带，改善了对可见光的吸收和功率转换效率。由于较高的电荷载流子有效质量比，因此较低的复合率，我们建议将Sn掺杂的CuAlS ₂用作有前途的材料，这表明基于CuAlS ₂的薄膜太阳能电池的性能得到改善。