摘要
在室温下系统地观测了多孔硅样品的光致发光谱随激发光波长的变化．在激发波长为２６０—３２０ｎｍ范围内，光致发光谱出现明显的双峰结构，两峰峰位分别位于６１０ｎｍ和７００ｎｍ波长附近．当激发波长由２６０ｎｍ开始逐渐增加时，短波峰与长波峰强度之比先增加，随后达极大值，它略大于１，以后，此比值急剧减小，逐渐趋于零，即只存在单一长波峰．以上现象难于用量子限制模型解释．假设在包围纳米硅粒的二氧化硅层中存在两种发光中心，可以用量子限制／发光中心模型来解释上述实验现象．
Abstract We have systematically measured the variation of photoluminescence (PL) spectra from porous silicon at room temperature with excitation wavelengths. In the range of excitation wavelength from 260 to 320um, the PL spectra show clear double-peak structure. The positions of the Two peaks are located around 610um and 700um, respectively.The relative intensity ratio of the PL peak at shorter wavelength to that at longer wavelength increases firstly with excitation wavelength, then reaches a maximum value slightly larger than 1. When the excitation wavelength increases further, the ratio decreases rapidly and tends gradually towards zero, only the PL peak at longer wavelength exists at last.The above phenomenon seems hard to be interpreted by using the quantum confinement model, but can be understood in the quantum confinement/luminescence centers model, if we suppose that there are two kinds of luminescence centers in SiO2 layers outside nanoscale silicon.
