仿生P/N异质结消反射复合涂层的创制及光电性能的研究

Biomimetic materials are developed using inspiration from nature, having been applied in the field of antireflection. On the basis of our previous research and effective advanced research, we intend to fabricate bomimetic composite coating with P/N heterojunctions and antireflection, through the methods of anisotropic etching, in-situ chemical reaction and surface assembly. Then, we will focus on studying the influence of anisotropic etching silicon on the antireflection, the mechanism of nanomaterials growth induced by heterogeneous interface and the influence of growth condition on the antireflection, the mechanism of photon-generated charge separation induced by double P/N heterojunctions and the influence on the photoelectric conversion efficiency of bomimetic composite coating. Thus, we can overcome the limitation of the traditional two-dimensional antireflective coating by spectral region and incident angle , and overcome the limitation of the traditional single-material antireflective coating by only reducing the light reflection. It's really worth expecting that three-dimensional biomimetic composite coating with double P/N heterojunctions will been obtained, showing a lower reflection, a broader spectral region, and a higher incident angle than the traditional two-dimensional antireflective coating . This study not only contributes to the development of the preparation of bomimetic materials with multifunction , but also provides important theoretical basis and practical value for the development of high energy materials.

仿生材料是指模仿生物的各种特点或特性而研制开发的材料，特别是在降低光在材料表面反射的领域具有广泛的应用。本研究基于前期的工作和有效的预研，拟通过湿法各向异性刻蚀、原位化学反应和界面诱导组装等，实现在具有锥形阵列的单晶硅表面有序构筑过渡金属氧化物和导电高分子的层级仿生功能涂层。重点研究各向异性刻蚀单晶硅对消反射性能的影响、异质界面诱导纳米材料生长的机理及对消反射性能的影响、双层P/N异质结的协同分离光生电荷的机理及对材料光电转化效率的影响等方面。从而克服传统的二维消反射涂层受波段和入射角的限制，同时也克服了传统单一材料消反射涂层只考虑降低光反射的局限性。以期开发获得具有双层P/N异质结的三维仿生消反射复合结构，其兼具广角-宽波段、低反射、高效分离光生电荷的优异性能。本研究不仅有助于发展制备多功能仿生涂层，而且为高效能源材料的开发提供重要理论依据和实用价值。

以热力学为指导，通过湿法各向异性刻蚀、原位化学反应、软模板压印和界面诱导组装等方法，实现在具有锥形阵列的单晶硅(Si)表面有序构筑过渡金属氧化物（TiO2）和导电高分子(聚苯胺PANI)的三维仿生复合涂层（PANI/TiO2（棒状）/Si以及PANI/TiO2（微金字塔）/Si）。通过界面动力学调控，实现仿生复合涂层的结构形貌可调，光电性能可调，并对不同的形貌与结构对复合涂层的抗反射性能、光电性能和光催化性能的影响进行评估。构筑的三元微纳仿生结构一方面增加了表面的粗糙度，提供更多的活性位点；一方面提高光的吸收率、拓宽光谱吸收范围；而且在TiO2和Si、PANI和TiO2之间形成的双层PN异质结有效提高了材料的光生电荷分离效率，在以上三方面的协同作用下，这种三元仿生复合材料具有优异的抗反射性能、高效的光电转化效率、较好的自清洁功能及良好的光催化效率。为了说明三元仿生结构对材料各项性能的决定性作用，将组成分子进一步扩展到MoS2/TiO2/Si三元体系，将其做成电极材料应用于光电分解水制氢，表现出优秀的光电催化性能。