原位等离子体逐层氧化a-Si:H/SiO2多层膜的光致发光研究

采用在等离子体增强化学汽相沉积系统中沉积a-Si:H和原位等离子体逐层氧化的方法制备a-Si:H/SiO2多层膜.改变a-Si:H层的厚度，首次在室温下观察到来自a-Si:H/SiO2多层膜较强的蓝色光致发光和从465到435nm的蓝移.x射线能谱证明，SiO2层是化学配比的SiO2；C-V特性表明，a-Si:H/SiO2界面得到了很好的钝化；透射电子显微镜表明，样品形成了界面陡峭的多层结构.结合光吸收谱和光致发光谱的研究，对其发光机理进行了讨论.用一维量子限制模型对光致发光峰随着a-Si:H层厚度的减小 关键词： a-Si:H/SiO2多层膜 光致发光

Photoluminescence from a-Si:H/SiO2 multilayers fabricated using in situ layer by layer plasma oxidation

a-Si:H/SiO2 multilayers were layer by layer deposited and in situ plasma oxidized in a plasma-enhanced chemical vapor deposition system. Strong and stable blue photoluminescence at room temperature was observed from the as fabricated a-Si:H/SiO2 multilayers. By controlling the thickness of the a-Si:H sublayer from 4 to 1.5nm,the photoluminescence peak blueshifts from 465 to 435?nm. X-ray photo electron spectroscopy indicates that the oxide layer is of stoichiometric SiO2. Good passivation of a-Si:H/SiO2 interface is testified by C-V. Periodical structure and sharp a-Si:H/SiO2 interface is shown by transmission electron microscope. Combined with the measurements of absorption and photoluminescence, the origin of blue photoluminescence is attributed to the recombination of electrons and holes near the band-tail in a-Si:H sublayer under one-dimensional quantum confinement effect.
Keywords： a-Si:H/SiO2 mutilayers blue photoluminescence