The absorption, reflection and photoluminescence spectra of GaSe crystals with different thicknesses (100 nm–1 mm) were investigated in a wide temperature interval (300 K–10 K). Features due to excitonic states in the spectra were recognized. The contours of the excitonic reflection spectra measured at 10 K were calculated by dispersion equations. On the basis of these calculations, the parameters of the observed excitons were determined. Photoluminescence spectra from the cleaved surface and from the uncleaved facet of a sample were measured at low temperatures.

中文翻译：

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GaSe单晶中的Wannier–Mott激子

在较宽的温度区间（300 K-10 K）内研究了厚度不同（100 nm-1 mm）的GaSe晶体的吸收，反射和光致发光光谱。识别出由于光谱中的激子态而引起的特征。通过色散方程计算在10 K下测得的激子反射光谱的轮廓。基于这些计算，确定了观察到的激子的参数。在低温下测量来自样品的劈开表面和未劈开小平面的光致发光光谱。