论文部分内容阅读
用脉冲激光沉积(PLD)的方法生长了掺Er Si(2nm)/Al2O3(1.5nm)多层薄膜,后期对其进行不同温度下的快速热退火(RTA)处理。在非Er离子(Er3+)共振激发476nm激光激发下,该薄膜得到来自于Er3+的室温特征光致发光(PL)谱,波峰波长为1.54μm,说明这种掺ErSi/Al2O3多层薄膜存在间接激发发光过程,退火得到的纳米Si在其中起到感光剂作用。分析了不同的退火温度对薄膜发光强度的影响,发现退火温度700℃时薄膜发光最强,其强度是同种方法制备的掺ErAl2O3薄膜的39倍。进一步结合不同退火温度下薄膜的喇曼散射谱分析发现,700℃退火的薄膜中Si虽然仍为非晶,但其中已出现数量较多的纳米Si团簇,它们是Er3+1.54μm发光的有效感光剂,增强了Er3+发光。而当温度高于700℃后,薄膜中纳米Si团簇已逐渐结晶,出现纳米Si晶粒,同时这种纳米Si晶粒尺寸随温度升高而变大、数量变少,带来的是作为感光剂的纳米Si数量的减少,导致Er3+薄膜发光强度减弱。因此在远低于纳米Si结晶所需的温度(一般需要高于900℃)下实现了掺ErSi/Al2O3多层薄膜中Er3+1.54μm的最优发光。
The Er doped Si (2nm) / Al 2 O 3 (1.5nm) multilayer thin films were grown by pulsed laser deposition (PLD), and then were rapidly annealed at different temperatures (RTA). The room-temperature characteristic photoluminescence (PL) spectra obtained from Er3 + at a wavelength of 1.54μm were obtained under excitation of non-Er (+) ions at a resonance excitation of 476nm, indicating that this ErSi / Al2O3 multilayer thin film has indirect excitation The light-emitting process, annealing the resulting nano-Si play a role in the sensitizer. The effect of different annealing temperature on the luminescence intensity of the film was analyzed. It was found that the luminescence of the film was the strongest at 700 ℃ and the intensity was 39 times higher than that of the ErAl2O3 film prepared by the same method. Furthermore, the results of Raman scattering spectra of thin films annealed at different annealing temperatures show that although Si is still amorphous at 700 ℃, a large number of Si clusters have been found, which are effective at emitting Er3 + 1.54μm Sensitizer, enhanced Er3 + light. However, when the temperature is higher than 700 ℃, the nano-Si clusters in the film have gradually crystallized and the nano-Si grains appear. At the same time, the size of the nano-Si grains becomes larger and smaller with increasing temperature, The amount of nano-Si sensitizer decreases, resulting in Er3 + thin film luminescence intensity weakened. Therefore, the optimal luminescence of Er3 + 1.54μm in ErSn / Al2O3-doped multi-layered thin films was achieved at much lower temperature than that of nano-Si crystals (generally higher than 900 ℃).