Temperature: a critical parameter affecting the optical properties of porous silicon
温度：影响多孔硅光学特性的一个关键参数

The optical properties of porous silicon (PS) samples fabricated by pulse etching in a temperature range from-40to 50_C have been investigated using reflectance spectroscopy, photoluminescence spectroscopy, and scanning electron microscopy (SEM). The dependence of the optical parameters, such as the refractive index n and the optical thickness (nd) of PS samples, on the etching temperature has been analyzed in detail. As the etching temperature decreases, n decreases, indicating a higher porosity, and the physical thickness of PS samples also de-creases. Meanwhile, the reflectance spectra exhibit a more intense interference band and the interfaces are smoother. In addition, the intensity of the PL emission spectra is dramatically increased.