掺铒Al_2O_3/Si多层薄膜中纳米晶Si的形成和敏化效应

采用脉冲激光沉积制备了掺铒Al2O3/Si多层薄膜,在淀积过程中脉冲激光溅射产生的高能量Er原子渗透进入非晶硅层,并引入了额外的应力,在低退火温度下诱导形成纳米晶Si。利用纳米晶Si作为敏化剂有效地增强了Er3+在Al2O3中的光致发光。样品微观结构和发光强度的关系表明,获得高密度和小尺寸的纳米晶Si和Er3+处于良好的发光环境是实现优化发光的关键,最优化的Er3+发光强度在退火温度为600℃的条件下得到。

Formation and Sensitizing Effects of Silicon Nanocrystais in Er-doped Al2O3/Si Multilayers

Er-doped Al2O3/Si multilayers have been fabricated by pulsed laser deposition.Thanks to the presence of energetic Er species produced by pulsed laser deposition,a shallow implantation of Er atoms into Si layers is achieved during the deposition process.The doped Er atoms induce additional strains in the amorphous Si layers and serve as nucleation centers to induce the formation of Si nanocrystals at low annealing temperatures.When Si nanocrystals are introduced as sensitizers,the photoluminescence of Er3+ in Al2O3 is greatly enhanced.The optimized photoluminescence is achieved at annealing temperature of 600°C,where a high density of small Si nanocrystals and a good local environment of Er3+ are crucial,then the photoluminescence gradually decreases as the annealing temperature increases.