This experimental work reports refractive index, extinction coefficients, and dielectric functions at different incident angles in visible range for the first time. The refractive index of CsPbI₃ thin film is 2.46 at 435 nm with this result implies that Cs based lead halide solar cells may be, ideal antireflection coating for many tandem solar cells. Thus lower refractive index of CsPbI₃ inorganic perovskite material is beneficial for perovskite device fabrications because of the minimum light looses to reflection at the front of the active layer. Furthermore microstructure of the cubic phase Pm-3 m was investigated by X-ray diffraction. CsPbI₃ perovskite thin film showed the sharp absorption edge and PL emission near infrared region with direct band gap of 1.67 eV with high color purity of red emission. In addition, the higher dielectric function value of CsPbI₃, will helps to many optoelectronic devices.

这项实验工作首次报告了可见光范围内不同入射角下的折射率，消光系数和介电函数。CsPbI ₃薄膜在435 nm处的折射率为2.46，该结果表明Cs基卤化铅太阳能电池可能是许多串联太阳能电池的理想抗反射涂层。因此，较低的CsPbI ₃无机钙钛矿材料的折射率对于钙钛矿器件的制造是有利的，因为在活性层的正面，最小的光散失到反射。此外，通过X射线衍射研究了立方相Pm-3 m的微观结构。CsPbI ₃钙钛矿薄膜在红外区域具有明显的吸收边缘和PL发射，直接带隙为1.67 eV，红色发射的色纯度高。另外，较高的CsPbI ₃介电函数值将有助于许多光电器件。