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采用快速热退火(RTA)对热丝化学气相沉积HWCVD制备的非晶氢-硅(a-Si:H)薄膜进行晶化处理,并在此基础上制备了纳米晶氢-硅(nc-Si:H)薄膜p-n结。利用拉曼(Raman)光谱、X射线衍射(XRD)、扫描电子显微镜(SEM)和分光光度计研究了所制备(nc-Si:H)薄膜的结构、光学性能与退火温度的关系;同时,研究了不同RTA条件下制备p-n结的整流特性随温度变化的规律。研究发现,随RTA温度由700℃升高至1 100℃,薄膜的晶化率由46.3%提高到96%,拉曼峰半高宽(FWHM)由19.7cm-1降低至7.1cm-1。当退火温度为700℃时,薄膜的XRD谱中只有一个较弱的Si(111)峰;当退火温度高于900℃时,薄膜的XRD谱中除Si(111)峰外,还出现了Si(220)、Si(311)峰。同时,随退火温度的升高,薄膜的禁带宽度由1.68eV升高至2.05eV。由于禁带宽度的增加,相应的p-n结最高工作温度也由180℃升高至300℃。
The amorphous hydrogen-silicon (a-Si: H) thin films prepared by hot filament chemical vapor deposition (HWCVD) were crystallized by rapid thermal annealing (RTA) : H) Film pn junction. The structure, optical properties and annealing temperature of the prepared (nc-Si: H) thin films were investigated by Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and spectrophotometer. The regularity of the rectifying characteristics of pn junction with temperature under different RTA conditions was studied. It was found that the Raman peak FWHM decreased from 19.7 cm-1 to 7.1 cm-1 with RTA increasing from 700 ℃ to 1100 ℃. The crystallization rate increased from 46.3% to 96%. When the annealing temperature is 700 ℃, there is only one weaker Si (111) peak in the XRD spectrum of the film. When the annealing temperature is higher than 900 ℃, the XRD spectrum of the film appears in addition to Si (111) (220), Si (311) peak. Meanwhile, with the increase of annealing temperature, the forbidden band width of the film increases from 1.68eV to 2.05eV. Due to the increase of the forbidden band, the corresponding maximum operating temperature of the p-n junction also increases from 180 ℃ to 300 ℃.