镶嵌有纳米硅的SiN_x薄膜光致发光的温度依赖特性研究

Temperature-Dependent Photoluminescence Property Studies of SiN_x Films with nc-Si

采用对靶磁控溅射法在单晶硅衬底上沉积镶嵌有纳米硅的氮化硅薄膜,然后在形成气体FG(10%H2,90%N2)气氛中进行450℃常规热退火50min。通过荧光光谱仪测得的稳态/瞬态光致发光(PL)谱研究了镶嵌有纳米硅的氮化硅(SiNx)薄膜样品光致发光特性。结果表明,样品的发光过程可以归因于纳米硅的量子限制效应发光和与缺陷相关的发光。随着激发光能量的增加,PL谱峰位发生蓝移,表明较小粒度的纳米硅发光比例增加;温度的降低会抑制非辐射复合过程,提高辐射复合几率,因此发光寿命延长,发光强度呈指数增加;随着探测波长的减小,样品的发光寿命则明显缩短,表明纳米硅的量子限制效应发光对温度有很强的依赖性。

Silicon nitride（SiNx）films containing nanocrystalline silicon（nc-Si）were deposited on crystalline silicon substrate by facing-target sputtering technique.Thermal annealing process was performed at 450 ℃for 50 min in a conventional furnace under FG（10%H2,90%N2）ambient.The photoluminescece（PL）properties of the SiNxfilms with nc-Si were investigated by steady/transient PL spectra measurements by Fluorescence spectrometer with different temperatures.The PL processes could be attributed to the quantum confinement effect of nc-Si and the defects in the film.The PL peak position exhibits a small blue shift with the increasing of the excitation energy,which indicates that the PL portion of the nc-Si increased with smaller size.In addition,the PL lifetime increases and the PL intensity exhibits exponential increase as a result of the decreased temperature which supressed the nonradiative recombination process and then improved the radiative recombination.The PL lifetime of the film significantly reduces with the decreasing of the detection wavelength,which indicates that the PL process related to the the quantum confinement effect strongly depends on temperature.