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本文在微晶硅材料性能研究的基础上制备了微晶硅薄膜晶体管(TFT).发现微晶硅的柱状生长模式会导致其结构和电学性能的不均匀性.由于材料的柱状生长模式使得其晶化百分比、晶粒尺寸和暗电导受到薄膜厚度的调制.平行于衬底和垂直于衬底方向的电导率随着材料沉积条件的变化呈现出不同的变化规律,后者始终保持在 10-6 s/an~10-5 s/cm 量级.确定了用于 TFT 有源层的微晶硅薄膜沉积条件中的硅烷浓度应高于 2%,晶化百分比应为40%~50%左右.制备的微晶硅 TFT 器件具有良好的稳定性,开态电流的衰退和阈值电压的漂移分别为 25%和1 Ⅴ,进而还发现了一种新颖的自恢复现象. 相似文献
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对微晶硅薄膜晶体管,尤其对底栅型晶体管,在衬底和晶化层间存在一层非晶相起始层,这将严重影响器件性能.文中采用降低硅烷浓度的方法简便有效地减薄了用超高频化学气相法直接沉积的微晶硅薄膜起始层的厚度,得到起始层厚度小于20nm的微晶硅薄膜.在硅烷浓度为2%的条件下采用四版工艺制备了具有Al/SiNx/μc-Si/n+-μc-Si/Al结构的底栅微晶硅TFT,其开关比(Ion/Ioff)达到106,场效应迁移率为0.7cm2/(V·s),阈值电压为5V左右. 相似文献
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采用超高频(VHF)结合高压(HP)的技术路线,在较高SiH4浓度(SC)下实现了微晶硅(μc-Si:H)薄膜的高速沉积,考察了衬底温度在化学气相沉积(CVD)过程中对薄膜的生长速率以及光电特性的影响.结果表明:薄膜微结构特性随衬底温度变化是导致薄膜电学特性随衬底温度变化的根本原因;HP与低压条件下沉积的μc-Si:H薄膜的特性随温度变化的规律不同,在试验温度范围内,HP高速沉积的μc-Si:H薄膜生长速率不同于低压时随温度升高而下降的趋势,而是先增大后趋于平稳,晶化率随温度升高也不是单调增加,而是先增加后减小. 相似文献
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八羟基喹啉镉薄膜制备及其光学特性 总被引:1,自引:0,他引:1
用真空蒸镀方法,在玻璃衬底上制备了衬底温度不同的八羟基喹啉镉薄膜.XRD分析表明,八羟基喹啉镉薄膜呈多晶态,且衬底温度越高,衍射峰越强,薄膜的结晶性能逐渐变好,结晶晶粒尺度也越大.AFM研究表明,衬底温度升高,薄膜表面形貌越均匀有序,质量变好.MM-16相调制型椭圆偏振光谱仪研究发现,衬底温度升高导致反蒸发增强,薄膜生长速率减小,随着入射光波长的增加,薄膜的折射率和消光系数逐渐减小.随着衬底温度升高,因薄膜晶粒尺度增大,折射率和消光系数也增大;并给出了它们的变化范围. 相似文献
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用真空蒸镀方法,在玻璃衬底上制备了衬底温度不同的八羟基喹啉镉薄膜.XRD分析表明,八羟基喹啉镉薄膜呈多晶态,且衬底温度越高,衍射峰越强,薄膜的结晶性能逐渐变好,结晶晶粒尺度也越大.AFM研究表明,衬底温度升高,薄膜表面形貌越均匀有序,质量变好.MM-16相调制型椭圆偏振光谱仪研究发现,衬底温度升高导致反蒸发增强,薄膜生长速率减小,随着入射光波长的增加,薄膜的折射率和消光系数逐渐减小.随着衬底温度升高,因薄膜晶粒尺度增大,折射率和消光系数也增大;并给出了它们的变化范围. 相似文献
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低温高速率沉积非晶硅薄膜及太阳电池 总被引:1,自引:0,他引:1
采用射频等离子体增强化学气相沉积(RF-PECVD)技术,保持沉积温度在125℃制备非晶硅薄膜材料及太阳电池。在85 Pa的低压下以及400~667 Pa的高压下,改变Si H4浓度和辉光功率等沉积参数,对本征a-Si材料的性能进行优化。结果表明,在高压下,合适的Si H4浓度和压力功率比可以使a-Si材料的光电特性得到优化,并且薄膜的沉积速率得到一定程度的提高。采用低压低速和高压高速的沉积条件,在125℃的低温条件下制备出效率为6.7%的单结a-Si电池,高压下本征层a-Si材料的沉积速率由0.06~0.08 nm/s提高到0.17~0.19 nm/s。 相似文献
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高压高功率VHF-PECVD的微晶硅薄膜高速沉积 总被引:2,自引:2,他引:0
采用高压高功率(hphP)甚高频等离子体强强化学气相沉积(VHF-PECVD)法对微晶硅(μc-Si:H)进行高速沉积,在最优沉积条件参数下对hphP和低压低功率(lplP)两组样品沉积速率、光电导、暗电导及光敏性等性能参数进行测试,得到了1.58 nm/s的较高沉积速率、光电性能优秀和更适合薄膜太阳能电池的μc-Si... 相似文献
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在掺杂P室采用甚高频等离子体增强化学气相沉积(VHF—PECVD)技术,制备了不同硅烷浓度条件下的本征微晶硅薄膜.对薄膜电学特性和结构特性的测试结果分析表明:随硅烷浓度的增加,材料的光敏性先略微降低后提高,而晶化率的变化趋势与之相反;X射线衍射(xRD)测试表明材料具有(220)择优晶向.在P腔室中用VHF—PECVD方法制备单结微晶硅太阳能电池的i层和p层,其光电转换效率为4.7%,非晶硅/微晶硅叠层电池(底电池的p层和i层在P室沉积)的效率达8.5%. 相似文献
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Modulation frequency and pulse duty cycle are two key parameters of pulsed VHF-PECVD technology. An experimental study on the mierocrystalline silicon materials prepared by pulsed VHF-PECVD technology in high deposition rate is presented. And combining the diagnosis of plasma process with optical emission spectroscopy (OES), the dependence of microstructure and electrical properties of thin films on the pulse modulation frequency is discussed in detail. 相似文献
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Hitoshi Sai Takuya Matsui Kimihiko Saito Michio Kondo Isao Yoshida 《Progress in Photovoltaics: Research and Applications》2015,23(11):1572-1580
Dielectric films with anti‐reflective sub‐wavelength structures are applied to thin‐film silicon solar cells to improve the light incoupling at the front surface. It is verified that modification of the refractive index of the incident medium using dielectric films with sub‐wavelength structures is beneficial to reduce the average reflectivity of Si solar cells with an anti‐reflective coating based on optical interference. It is also shown that the sub‐wavelength structure must be combined with a proper light‐trapping texture to enhance the absorption within thin‐film silicon solar cells. The effectiveness of dielectric films with sub‐wavelength structures is demonstrated by an increase of the short‐circuit current density of a microcrystalline silicon cell from 29.1 to 30.4 mA/cm2 in a designated area of 1 cm2. The optical interplay between the dielectric films and the light‐trapping textures is also discussed. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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C. Ross Y. Mai R. Carius F. Finger 《Progress in Photovoltaics: Research and Applications》2011,19(6):715-723
A detailed structural analysis is provided by which the benefits of thin undoped ‘seed layers’ for the preparation of microcrystalline silicon on glass for material characterization are demonstrated. Raman spectroscopy and photothermal deflection spectroscopy (PDS) results reveal that ‘seed layers’ are not only effective for the growth of structurally homogenous films and for an extension of the range of deposition parameters in which highly crystalline material is grown, but also allow for preparing material on glass with properties very close to that of functional layers in thin film solar cells. Films which have successfully been tailored in this way are characterized with respect to electrical conductivity and optical absorption. Regarding conductivity, hydrogenated microcrystalline silicon material grown on a ‘seed layer’ exhibits a structure‐dependent behaviour which is very similar to that observed for material grown on bare glass. Regarding optical absorption spectra, residual interference fringes, which indicate structural non‐uniformities, can be successfully removed by means of ‘seed layers’. As a result, more information is obtainable from PDS, and the data gained in this way are in good agreement with Raman spectroscopy results. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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