梯度带隙氢化非晶/纳米硅复合光敏层的构建及其性能研究

Optically addressed liquid crystal spatial light modulators (OASLMs) are devices that modulate the optical field distribution of the light wave. They have extensively been used in many application areas, such as optical information processing, beam transformation, wavefront correction, output shows and so on. The property of the photosensitive functional layer has a direct impact on the overall device performance. The project will introduce the novel gradient band gap hydrogenated nano silicon thin film composite materials into the photosensitive layer. on the base of establishing hydrogenated amorphous/nanocrystalline silicon composite films AC impedance theoretical model.Using the radio-frequency (RF) magnetron sputtering method, we can efficiently control the optical band gap of the thin film by regulating the grain size and crystallization of the micro-boron-doped nanocrystalline silicon film, thus we can prepare the composite photosensitive layer of the gradient band gap with PIN structure of hydrogenated amorphous / nanocrystalline silicon. In the P and I layer thickness meet the liquid crystal spatial light modulator impedance matching conditions，through the P and I layer gradient band gap formation and two layers of relative thickness changes, Regulated photosensitive layer of spectral response curve, make its and incident spectral matching. maximize absorbed incident photons to improve the photoelectric conversion efficiency. so we can enhance the sensitivity of photosensitive layer, realize the modulation of the optically addressed liquid crystal spatial light modulator in the dim light.

光寻址液晶空间光调制器是一种对光波的光场分布进行调制的元件，广泛地应用于光信息处理、光束变换、波前校正、输出显示等诸多领域，其光敏功能层的性能直接影响着整体器件的性能。本项目将新颖的梯度带隙氢化纳米硅薄膜复合材料引入到液晶空间光调制器光敏层中，在建立氢化非晶/纳米晶硅复合膜交流阻抗理论模型的基础上，利用射频磁控共溅射技术，通过调节微掺硼纳米硅膜的晶粒尺度和晶化度，有效地控制复合膜的光学带隙，进而应用于梯度带隙的氢化非晶/纳米晶硅PIN结构复合光敏层的制备，在P、I层厚度满足液晶空间光调制器阻抗匹配条件下，通过P、I层的梯度带隙的形成和两层的相对厚度的改变，调控光敏层的光谱响应曲线，使其和入射光谱匹配，最大限度地吸收入射光子，提高光电转换效率，从而提升光敏层的灵敏度，实现光寻址液晶空间光调制器在微光下的调制。

针对液晶光阀光敏层光电转换效率、灵敏度的提升需求，本项目在建立了轻掺杂硼纳米硅双相薄膜物理模型的基础上，结合射频磁控溅射和PECVD成膜技术，在高氢背底下, 通过轻掺B、Ge、低能电子束纳米晶化的方法，生长制备非晶/纳米硅薄膜。详尽分析研究了B、Ge、低能电子束对非晶硅的作用及非晶/纳米硅薄膜的生长机理、纳米尺度的控制、光学带隙的调控以及工艺参数对薄膜光电性能的影响，并采用RF-PECVD制备技术，逐步梯度改变锗烷、氢气的流量工艺，构建了渐变带隙光敏层，实现了光学带隙渐变，使光敏层的明暗电导比达到了5个数量级。在此基础上，提出了化合物(CdTe )掺杂纳米硅、金属(Ru、Ag)掺杂纳米硅及硅纳米线光敏层，通过射频磁控共溅射成膜技术与材料特性表征手段，深入研究了微观结构及光电特性的演变规律及其作用机理，并对潜在应用进行了探索。