Showing papers by "Youdou Zheng published in 1993"
TL;DR: In this article, an electrically induced visible light emitting porous silicon (PS) device was fabricated by laterally anodizing an n-type single-crystal silicon wafer.
Abstract: An electrically induced visible light emitting porous silicon (PS) device was fabricated by laterally anodizing an n‐type single‐crystal silicon (Si) wafer. Al/PS Schottky junctions exhibited rectifying I‐V characteristics with an ideality factor of 7. The intensity of current‐induced light emission increased with applied electrical current. Novel photocurrent spectra of the device under different reverse biases were measured at room temperature and reported for the first time, which showed three peaks of light absorption pertinent to the quantized energy levels of the PS. Interpretation is given based on the quantum confinement model.
21 citations
TL;DR: In this article, the photoluminescence spectra of porous GeSi and Si were investigated as a function of temperature (77-300 K) and showed that porous geSi has a quite different temperature dependence from that of porous silicon.
Abstract: Porous GeSi/Si heterostructures were fabricated by laterally anodization in HF-based solutions. Photoluminescence spectra have been investigated as a function of temperature (77–300 K), showing that porous GeSi has a quite different temperature dependence from that of porous silicon. Raman spectra indicated that the sample structure changed after anodization. Phonon participation and direct recombination of excitons are proposed to be responsible in the light emission processes of porous GeSi and Si, respectively.
4 citations
TL;DR: In this paper, the anomalous temperature dependence of photoluminescence (PL) from porous GeSi layer at 77-300 K was reported, where the peak energy of PL spectra from porous geSi layer decreases with increasing temperature while its peak intensity rises.
Abstract: Relaxed Ge0.5Si0.5/Si heterostructure was grown by the rapid radiant heating, very low pressure chemical vapor deposition (RRH-VLP/CVD). We report the anomalous temperature dependence of photoluminescence (PL) from porous GeSi layer at 77-300 K. The peak-emission energy of PL spectra from porous GeSi layer decreases with increasing temperature while its peak intensity rises, which is quite different from the temperature dependence of porous Si layer. Such dependencies are reversible and independent of temperature-change directions. No obvious 480 cm-1 peak was observed in Raman spectrum, indicating that no substantial amorphous phase contributes the intense light emission from the porous materials. We attribute such anomalous behavior of porous GeSi layer to phonon participation in the light-emission process of porous GeSi layer.