InAs基半导体材料的热光伏效应及其在低温辐射体热光伏发电中的应用基础研究

It has been becoming a hot research thesis for investigations on the thermophotovoltaic effect of narrow band gap semiconductors and on their applications of converting low energy photons from low temperature heat sources into electrical power. Researchers have found that the lower the heat source temperature is, the more stable and more reliable the thermophotovoltaic cells are, and these low temperature applications require narrow band gap cells. III-V InAs-based material is one of optimum material whose band gap closely matches to the peak emission wavelength of 500-1000oC heat source. InAs-based epilayer will be grown by liquid Phase Epitaxy, its thermophotovoltaic effects will be studied; InAs cells will be designed and fabricated, the basic working principle of cells will be investigated and the major factors affecting cells conversion efficiency should be analyzed. We will try to solve the problems of high background carrier concentration and high dark current for narrow band gap semiconductors by purification of rare earth metal and design of blocking layers. Carrier recombination mechanism should be studied. Carrying out this project would be helpful to have a deeper understanding for basic principle of carrier transportation and thermophotovoltaic conversion on narrow band gap semiconductor, which would play a significant role in the development of China's innovation ability in field of thermophotovoltaic energy conversion.

窄禁带半导体材料的热光伏效应及其在相对低温（500-1000oC）辐射体光伏发电方面的应用已成为当今国际的研究热点。研究表明辐射源的温度越低，电池的稳定性越好，可靠性越高。III-V族InAs基材料的禁带宽度位于此温区对应的红外辐射能量范围，是最佳的带隙匹配材料之一。本项目拟在我们组原有工作基础上，采用液相外延技术生长高质量的InAs基外延膜，研究它的热光伏效应和决定热光伏响应大小的内在机制；以此为基础设计制作热光伏电池并优化其结构与性能,了解电池工作的基本物理过程和制约电池转换效率的主要因素；通过掺杂优化、阻挡层设计等方法解决窄带隙半导体中背景载流子浓度高、漏电流大的难题，揭示InAs基材料及相应电池中载流子的复合机理。项目的实施有助于加深了解窄带隙半导体中载流子的输运特性和热光伏转换机制等基本科学问题，相关研究成果对提升我国在国际热光伏发电领域的研究水平，增强自主创新能力具有重要作用。

窄禁带半导体材料的热光伏效应及其在相对低温(500-1000oC)辐射体发电方面的应用已成为当今国际的研究热点。研究表明辐射源的温度越低，电池的稳定性越好，可靠性越高。本项目设计研发了具有自主知识产权的液相外延设备；提出了基于液相外延技术的InAsSbP势垒阻挡层结构，有效地抑制了热光伏电池的暗电流；采用稀土吸杂机理的组合式纯化方法强效抑制了背景载流子浓度，使InAs吸收层室温载流子浓度控制在9.5×1015 cm-3～2.9×1016 cm-3，室温电子迁移率控制在2.0×104 ～2.9×104 cm2/Vs；热光伏电池内量子转换效率大于80%，最大能量转换率达6.5%；研究了电池工作的基本物理过程和制约电池转换效率的主要因素；揭示了InAs基热光伏电池中载流子的复合机理。项目研究对提升我国在国际热光伏发电领域的研究水平，增强自主创新能力具有重要作用。