Microstructure and optical response optimization of Ge/Si quantum dots transformed from the sputtering-grown Ge thin film by manipulating the thermal annealing
Microstructure and optical response optimization of Ge/Si quantum dots transformed from the sputtering-grown Ge thin film by manipulating the thermal annealing
复制标题
通过控制热退火从溅射生长的 Ge 薄膜转化的 Ge/Si 量子点的微观结构和光学响应优化
DOI：
10.1088/1361-6528/aaa2dd
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发表时间：
2018
期刊：
影响因子：
3.5
通讯作者：
Yang Yu
中科院分区：
文献类型：
--
作者：
Shu Qijiang;Wang Rongfei;Yang Jie;Zhang Mingling;Zeng Tianjian;Sun Tao;Wang Chong;Yang Yu
采用传统的直流磁控溅射法生长二维Ge薄膜，通过调节退火工艺，诱导Ge薄膜发生相变，制备了一系列零维Ge/Si量子点样品。后快速热退火（PRTA）后，量子点密度急剧增加。原子力显微镜（AFM）和拉曼光谱的观察结果表明，Ge量子点的良好形貌是由于Ge-Si晶格失配、薄膜表面温度以及Ge和Si之间的热膨胀系数差异共同作用形成的热力学和动力学环境的结果。在17 K时，在单层Ge量子点中检测到Ge量子点的光致发光峰.由超高密度量子点样品制备的金属-Ge/Si量子点-金属（MGM）光电探测器表现出相对较高的电流增益、绝对光电响应率和内量子效率（IQE）。研究结果表明，采用调制直流磁控溅射和PRTA工艺可以制备出具有强光吸收和量子限制效应的高质量Ge量子点。这为通过传统的、相对低成本的、大规模生产的纳米材料制备方法实现高性能的硅基光电子器件铺平了道路。
A series of zero-dimensional Ge/Si quantum dots (QDs) samples are fabricated by inducing the transformation from the two-dimensional Ge thin film, which is grown by the traditional direct current (DC) magnetron sputtering, via regulating the annealing process. The QD density increases sharply after the post rapid thermal annealing (PRTA). The observations of atomic force microscopy (AFM) and Raman spectroscopy suggest that the good morphology of Ge QDs results from an appropriate thermodynamics and kinetics surrounding shaped by the cooperative interaction of the Ge–Si lattice mismatch, the film’s surface temperature, and the difference in thermal expansion coefficients between Ge and Si. The photoluminescence (PL) peaks of Ge QDs are detected in monolayer Ge QDs with ultrahigh density at 17 K. The Metal-Ge/Si QDs-Metal (MGM) photodetector fabricated from the ultrahigh-density QDs sample exhibits a relatively high current gain, absolute photoelectric responsivity, and internal quantum efficiency (IQE). Our results demonstrate that the high-quality Ge QDs with strong light absorption and quantum confinement effect can be realized by modulating DC magnetron sputtering and the PRTA process. This paves the way for realizing silicon-based optoelectronic devices with high performance by the traditional, relatively low-cost, and large-scale production nanomaterial fabricating method.