有机吸附物对多孔硅微腔发光的影响

理论上，采用Bruggeman有效介质近似，研究了有机吸附物对多孔硅微腔的折射率及其光致发光谱的影响.实验上，采用计算机控制的电化学腐蚀法制备了多孔硅微腔样品，并利用机械泵油的蒸气分子与该微腔样品进行相互作用.研究发现，多孔硅微腔发射的窄化光致发光谱对泵油蒸气分子的吸附与脱附很敏感，与之伴随的是该窄化光致发光谱发生明显的峰位移动(可达71nm)和强度变化.结合Bruggeman近似和表面态对多孔硅发光的影响，对实验结果进行了定性解释.实验结果与理论模拟结果符合较好. 关键词： Bruggeman近似 吸附物 多孔硅微腔 光致发光谱

Effects of organic adsorbent on the photoluminescence of porous silicon microcavities

The effects of organic absorbent on the refractive index and photoluminescence of porous silicon microcavities were theoretically investigated by using the Bruggeman effective medium approximation. Experimentally， porous silicon microcavities were fabricated by computer controlled electrochemical etching， and then interacted with the molecules of oil vapor from a rotary pump. We found that the narrow photoluminescence spectra of porous silicon microcavities were sensitive to the adsorption and de-adsorption of the oil vapor molecules， which leads to a 71nm red-shift and the intensity variation in photoluminescence spectrum. The experimental results are qualitatively consistent with the theoretical estimate.