Enhanced luminescence from encapsulated silicon nanocrystals in SiO2 with rapid thermal anneal
Enhanced luminescence from encapsulated silicon nanocrystals in SiO2 with rapid thermal anneal
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DOI：
10.1016/j.vacuum.2006.03.023
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发表时间：
2006-09-20
期刊：
影响因子：
4
通讯作者：
Boyd, I. W.
中科院分区：
文献类型：
--
作者：
Iwayama, T. S.;Hama, T.;Boyd, I. W.
众所周知，硅离子注入到SiO2中，然后进行高温退火，可以形成嵌入的发光硅纳米晶体。在这项工作中，研究了快速热退火提高光致发光强度的潜力。采用离子注入法制备了不同浓度含过量硅的SiO2试样。在注入的样品中，硅析出形成纳米晶体是通过传统的炉内退火进行的。硅纳米晶体的光致发光强度和峰值发射能量与注入离子剂量有关。此外，在传统的炉内退火之前，通过快速热退火可以大大增强发光强度。发光强度。然而，在常规炉退火之后进行快速热退火则会降低。研究发现，热处理的顺序是影响发光强度的一个重要因素，发光峰值能量与试样的热历史有关，但仅受很小的因素影响。发现增强是低剂量样品的典型特征。此外，观察到长时间退火引起的饱和和发光的蓝移强烈表明，发射不仅仅是由于Si纳米晶体内部的电子-空穴复合。在实验结果的基础上，讨论了增强光致发光的机理，以及光致发光的机理。(c) 2006 Elsevier Ltd.版权所有。
It is well known that Si ion implantation into SiO2 and subsequent high-temperature anneals induce the formation of embedded luminescent Si nanocrystals. In this work, the potentialities of rapid thermal annealing to enhance the photoluminescence intensity have been investigated. Ion implantation was used to synthesize specimens of SiO2 containing excess Si with different concentrations. Si precipitation to form nanocrystals in implanted samples takes place with a conventional furnace anneal. The photoluminescence intensity and the peak energy of emission from Si nanocrystals depend on implanted ion dose. Moreover, the luminescence intensity is strongly enhanced with a rapid thermal annealing prior to a conventional furnace anneal. The luminescence intensity., however, decreases when rapid thermal annealing follows conventional furnace annealing. It is found that the order of heat treatment is an important factor in intensities of the luminescence and that the luminescence peak energy is found to be dependent, but only by a small factor, on the thermal history of specimens. Enhancement is found to be typical for low dose samples. Furthermore, the observation that the prolonged anneal induces saturation and a blue shift of the luminescence strongly indicates the emission is not simply due to electron-hole recombination inside the Si nanocrystals. Based on our experimental results, we discuss the mechanism for the enhancement of the photoluminescence, together with the mechanism of photoemission. (c) 2006 Elsevier Ltd. All rights reserved.