掺铒a-Si_xC_(1-x)-H薄膜的发光特性

Photoluminescence Properties of Er-doped SiC Thin Film

用等离子体增强化学气相沉积(PECVD)的方法,以固定的氢气(H2)流量和不同的硅烷(SiH4)和甲烷(CH4)流量比沉积了一系列的氢化非晶SiC(a-SixC1-x-H)膜。用这种宽带隙的a-SixC1-x-H材料作为掺铒的基体材料,通过离子注入的方法得到掺铒的a-SixC1-x-H(a-SixC1-x-H:Er)膜。注入以后的样品经过不同温度的退火。用X射线光电子能谱(XPS)、红外吸收光谱(IR)、拉曼散射谱(Raman)等技术研究不同的SiH4/CH4流量比和退火温度对a-SixC1-x-H:Er发光强度的影响。结果表明,高温退火引起了膜中C的分凝,对铒的发光是不利的。通过低温和室温下铒发光强度的比较,表明这种材料具有较弱的温度猝灭效应。

Hydrogenated amorphous silicon carbide （a-SixC1-x：H） films were grown on Si substrate by plasma-enhanced chemical vapor deposition. Fixed flow rate of H2 and different flow ratio of SiH4/CH4 were used. Er-doped a-SixC1-x ：H （a-SixC1-x-H：Er） films were prepared by implanting Er into the a- SixC1-x-H host materials followed by annealing at different temperatures. The structure properties of the films were characterized by X-ray photoelectron spectroscopy （XPS）, infrared absorption spectra （IR） and Raman spectra. Photoluminescence （PL） intensities depending on flow rates and annealing temperatures were studied. High annealing temperature is not favorable for PL because of C-surface segregation. It is shown that thermal quenching of this material is small by comparing the PL intensities of a-SixC1-x-H：Er at room temperature and low temperature.