论文部分内容阅读
经过激光辐照和高温退火加工能够生成多孔硅样品,在650—780 nm处检测到很强的光致荧光(PL)峰,并且有明显的钉扎和增强效应.实验表明,这种PL发光的强度与样品受辐照和退火的时间长短密切相关.通过第一性原理模拟计算发现,样品表面用Si O双键和Si—O—Si桥键钝化,能隙中会出现电子局域态.激光辐照和高温退火的时间长短决定了样品表面Si O双键和Si—O—Si桥键的密度,而该密度正是影响多孔硅量子点中电子局域态生成的关键.
After laser irradiation and high temperature annealing process can produce porous silicon samples, strong photoluminescence (PL) peak was detected at 650-780 nm, and there are obvious pinning and enhancement effect.Experiments show that this PL luminescence Is closely related to the length of time the sample is irradiated and annealed.The first-principles simulation results show that the surface of the sample is passivated by Si O double bond and Si-O-Si bridge bond, and the electron localized region The length of laser irradiation and high temperature annealing determine the density of Si O double bonds and Si-O-Si bridge bonds on the sample surface, which is the key factor that affects the electronic localization in porous silicon quantum dots.