Blue-violet photoluminescence from amorphous Si-in-SiNx thin films with external quantum efficiency in percentages
Blue-violet photoluminescence from amorphous Si-in-SiNx thin films with external quantum efficiency in percentages
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DOI：
10.1063/1.2179613
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发表时间：
2006-02-27
影响因子：
4
通讯作者：
Cao, ZX
中科院分区：
文献类型：
--
作者：
Ma, LB;Song, R;Cao, ZX
通过等离子体增强化学气相沉积在冷基底上以循环生长模式制备的非晶Si-in-SiNx薄膜中获得了以428 nm为中心的明亮蓝紫色光致发光，其中硅颗粒的典型尺寸已降至约1.80 nm，数密度达到1.07x10(13) cm(2)。在沉积样品中测得最大外量子效率超过 3.0%。时间分辨光致发光光谱显示，即使在室温下，衰减时间也在纳秒内，揭示了该非晶系统中的快速复合动力学。优异的效率可归因于硅颗粒更好的钝化——因此，传统的快速热退火对光致发光强度的影响可以忽略不计——而且还归因于循环生长提高了薄膜的透明度。通过低温工艺无需任何后处理即可实现室温下的高效率、可调波长和纳秒衰减时间，这使得 Si-in-SiNx 系统成为光子和光电应用中发光纳米结构的有希望的候选者。
Bright blue-violet photoluminescence centered at 428 nm was obtained in amorphous Si-in-SiNx thin films prepared in a cyclic growth mode on cool substrates by plasma-enhanced chemical vapor deposition, in which the typical size of the silicon particles has been brought down to similar to 1.80 nm and the number density amounts to 1.07x10(13) cm(2). A maximum external quantum efficiency over 3.0% was measured in the as-deposited samples. Time-resolved photoluminescence spectra revealed decay times within nanosecond even at room temperature, disclosing a fast recombination dynamics in this amorphous system. The excellent efficiency can be attributed to a better passivation of the silicon particles-hence, the conventional rapid thermal annealing has a negligible effect on the photoluminescence intensity-and also to an improved transparency of the film by cyclic growth. The high-efficiency, tunable wavelength and nanosecond decay time at room temperature, achieved via a low-temperature process without invoking any posttreatment, combine to make the Si-in-SiNx system a promising candidate for light-emitting nanostructures in photonic and optoelectronic applications.