Ford Brian, Tabassum Natasha, Nikas Vasileios, Gallis Spyros
Colleges of Nanoscale Science and Engineering, SUNY Polytechnic Institute, Albany, NY 12203, USA.
Materials (Basel). 2017 Apr 23;10(4):446. doi: 10.3390/ma10040446.
The following study focuses on the photoluminescence (PL) enhancement of chemically synthesized silicon oxycarbide (SiCO) thin films and nanowires through defect engineering via post-deposition passivation treatments. SiCO materials were deposited via thermal chemical vapor deposition (TCVD), and exhibit strong white light emission at room-temperature. Post-deposition passivation treatments were carried out using oxygen, nitrogen, and forming gas (FG, 5% H₂, 95% N₂) ambients, modifying the observed white light emission. The observed white luminescence was found to be inversely related to the carbonyl (C=O) bond density present in the films. The peak-to-peak PL was enhanced ~18 and ~17 times for, respectively, the two SiCO matrices, oxygen-rich and carbon-rich SiCO, via post-deposition passivations. Through a combinational and systematic Fourier transform infrared spectroscopy (FTIR) and PL study, it was revealed that proper tailoring of the passivations reduces the carbonyl bond density by a factor of ~2.2, corresponding to a PL enhancement of ~50 times. Furthermore, the temperature-dependent and temperature-dependent time resolved PL (TDPL and TD-TRPL) behaviors of the nitrogen and forming gas passivated SiCO thin films were investigated to acquire further insight into the ramifications of the passivation on the carbonyl/dangling bond density and PL yield.
以下研究聚焦于通过沉积后钝化处理进行缺陷工程，来增强化学合成的碳氧化硅（SiCO）薄膜和纳米线的光致发光（PL）。SiCO材料通过热化学气相沉积（TCVD）制备，并在室温下呈现出强烈的白光发射。使用氧气、氮气和形成气体（FG，5% H₂，95% N₂）环境进行沉积后钝化处理，改变了观察到的白光发射。发现观察到的白色发光与薄膜中存在的羰基（C=O）键密度成反比。通过沉积后钝化，富氧和富碳SiCO这两种SiCO基体的峰-峰PL分别增强了约18倍和约17倍。通过组合式系统傅里叶变换红外光谱（FTIR）和PL研究表明，适当调整钝化可使羰基键密度降低约2.2倍，对应PL增强约50倍。此外，对氮气和形成气体钝化的SiCO薄膜的温度依赖和温度依赖时间分辨PL（TDPL和TD-TRPL）行为进行了研究，以进一步深入了解钝化对羰基/悬空键密度和PL产率的影响。
