高压条件下纳米晶硅的多激子产生特性研究

项目名称： 高压条件下纳米晶硅的多激子产生特性研究

项目编号： No.61504036

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 无线电电子学、电信技术

项目作者： 丛日东

作者单位： 河北大学

项目金额： 18万元

中文摘要： 纳米晶硅 III相（nc-Si III）因其低带隙和高多激子产生特性，具有重要的科学意义和潜在应用前景，成为第三代太阳能电池的优选材料。但受限于制备工艺，常规条件下难以获得适用于多激子产生（MEG）效应研究的nc-Si III结构，目前仅集中于理论探讨，尚缺少实验验证。本项目拟采用等离子体增强化学气相沉积技术结合退火技术制备多种晶粒尺寸、密度可控的nc-Si薄膜，利用成熟的原位金刚石压砧高压实验技术，研究该类材料在高压极端条件下的相变行为规律并探索其相变机制，寻找获得适用于MEG效应研究的nc-Si III结构的新方法。同时结合紫外可见吸收光谱和光致发光技术对高压下获得的nc-Si III相的能带结构特性以及MEG特性进行研究，探索利用压力对nc-Si薄膜物理性质进行调控的可行性，为nc-Si薄膜在高效光伏器件中的应用提供重要实验依据。

中文关键词： 纳米晶硅III；高压相变；能带结构；多激子产生

英文摘要： Nanocrystalline Si III (nc-Si III) has become a promising material for the third generation solar cell due to the properties of low band gap and high multiple exciton generation (MEG) yield, which possess important scientific significance and potential application prospect. However, the research on the MEG effect of the nc-Si III only concentrated on the theoretical studies as a result of the limited preparation process under normal conditions. In the project, we prepare nc-Si films with controllable crystalline size and density using plasma enhanced chemical vapor deposition (PECVD) and annealing technology. For the purpose of developing a new way for the obtaining of the nc-Si III structure suitable for the MEG study, the high-pressure phase transition behaviors and transition mechanisms of the nc-Si films are investigated using in situ diamond anvil cell high-pressure experimental technology. The ultraviolet visible absorption spectroscopy and photoluminescence spectra are used to study the energy band structure and MEG effect of the nc-Si III structure for the exploration of the feasibility for the properties control of the nc-Si films via high pressure. The results will provide an important experimental basis for the applications of the nc-Si films in efficient photovoltaic devices.

英文关键词： Nanocrystalline silicon III;High-pressure phase transition;Energy band structure;Multiple exciton generation