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硅常温下的禁带宽度仅1.1eV,且是间接跃迁型半导体。这是困扰光电子学几十年的老问题,多年来人们想尽各种掺杂办法,均未达到理想的结果,Canham用电化学刻蚀的办法在单晶硅片上形成多孔硅,然后停电继续腐蚀一段时间,制成高孔积率(80％以上)的多孔硅膜,在氩离子激光激发下,用肉眼就能观察到明显的红光发射,这一发现在光电子学领域引起了轰动。多孔硅早在30年前就已发现,在近10年内受到广泛注意,但主要是利用多孔硅形成良好的SiO_2电绝缘层,因此其孔积率一般不超过56％,Canham的第二步腐蚀是形成发光层的关键,而Bsiesy等则采用氧化的方法能达到同样的目的,到目前为止,大多数人认为这一现象是由量子效应引起的这种观点认为:在电化学形成多孔硅过程中,硅基
Silicon band gap at room temperature only 1.1eV, and is an indirect transition semiconductor. This is a longstanding problem that has plagued optoelectronics for decades. For years, people have tried various doping methods without achieving the desired results. Canham formed porous silicon on a monocrystalline silicon wafer by electrochemical etching and then powered down Continue to corrode for a period of time, made of porous silicon membrane with high Pore rate (more than 80%), the obvious red emission can be observed with the naked eye under argon ion laser excitation, which caused a sensation in optoelectronics field . As early as 30 years ago, porous silicon has been found to attract widespread attention in recent 10 years. However, porous silicon is mainly used to form a good SiO 2 electrical insulating layer. Therefore, the porous silicon has a porosity of not more than 56%. Canham’s second-step corrosion Is the key to the formation of the light-emitting layer, while Bsiesy and other methods of oxidation can achieve the same purpose, so far, most people think this phenomenon is caused by the quantum effect of this view: the formation of porous silicon in the electrochemical process In the silicon