6.1埃锑基热光伏电池热辐射管理研究

Thermophotovoltaic, converting infrared thermal irradiation into electricity by photovoltaic cell, has been regarded as an important strategy of the third generation photovoltaic technologies to conquer energy crisis. Under the suggested project, by analyzing deeply the origin of low efficiency dilemma suffered by current thermophotovoltaic, we will theoretically investigate the novel methods to enhance thermophotovoltaic system performance in the framework of thermal irradiation management. Firstly, on the basis of the antimony-based alloy semiconductors with lattice 6.1 angstrom, we will systematically study the intrinsic relationship between device structure performance and external thermal irradiation spectrum, revealing the impaction of various technical parameters on cell performance and establishing further the fundamental principle to construct new device structure of high performance-price ratio. Secondly, still based on the antimony-based alloy semiconductors, by investigating the theoretical relationship among bandgap combination, device structure, thermal irradiation spectrum, and performance output, we will establish novel strategies to enlarge the cut-off wavelength of cell spectrum response and construct new multiple-bandgap cell for high efficiency but low cost thermophotovoltaic applications. Finally, by investigating the light propagation in periodically dielectric structure and light scattering by nanoparticle, we will develop a series of irradiation management methods by designing proper surface anti-reflection coatings, spectrum filtering, and back-reflector structures to engineer the thermal irradiation spectrum. To sum up, we hope, in the framework of thermal irradiation management, to establish novel strategies to match the cell spectrum response with the thermal irradiation spectrum of general emitters, achieving the fully absorption, conversion, and output of thermal irradiated energy and providing further the solid scientific knowledge for the construction of new high performance thermophotovoltaic system.

热光伏技术利用光伏电池将红外热辐射转换为电能输出，是第三代光伏技术领域的重要前沿课题。本研究在综合分析热光伏技术低能量转化效率起因的基础上，从热辐射管理的新角度出发，首先立足于6.1Å锑基合金半导体材料，深入剖析锑基热光伏电池结构性能与热辐射谱之间的微观联系，揭示不同技术参数对电池性能的影响规律，确立高性价比电池结构制备的理论原则；以发展锑基多能隙电池器件为目标，综合研究多能隙器件中材料、器件、热辐射谱、以及性能之间的理论联系，探索拓展器件光谱响应能量区间的新方法，确立具有高效率、低成本光伏应用潜力的电池新结构；在此基础上，通过研究介电周期结构中光传输和纳米粒子光散射，确立与锑基电池相宜的表面减反射、光谱过滤、背反射等辐射管理系列新方案。通过研究实现电池光谱响应与选择性热辐射谱有效匹配的新途径，实现对热光伏系统中热辐射的有效管理，可望为新型高性能热光伏系统的构建提供系统化的科学依据。

本项目以6.1埃锑基合金为材料基础，重点从高效热光伏电池结构和相宜的光谱剪裁结构两个方面探索红外热辐射谱高效管理利用问题的集成化解决方案。项目组通过深入剖析锑基合金能带结构与材料光吸收物性的内禀联系，发展了可定量计算6.1埃锑基合金光吸收谱的有效方法，为相关器件结构性能的理论研究奠定了基础；系统研究了0.53 eV GaInAsSb热光伏电池结构性能，观察到器件轻掺杂层存在最优掺杂浓度3×1017 cm-3，且该最优掺杂与器件位型和外部辐照条件等技术参数无关，为相关高性能电池结构的实验制备确立了必要的理论准则；定量评估了电池前表面反射对器件光电转换性能的影响，发现表面反射损失主要会导致近40%左右的光电转换效率损失，而对器件最优结构的构筑方案影响不大，肯定了不考虑表面反射时器件结构性能研究成果的有效性；系统考察了锑基合金能隙对器件最优光电性能的影响规律，确立了最优结构随带隙变化的演变规律；基于细致平衡原理研究，提出了实验上可行的双结、三结锑基串联叠层电池结构，为高效热辐射的吸收转化提供了新的探索途径；系统研究了GaSb/0.53 eV GaInAsSb双结热光伏电池结构性能，确立了子电池最优“掺杂对”条件，观察到了S-型温度效率响应谱。总体而言，项目组以项目研究计划为主要参考，有效结合锑基热光伏电池领域的动态新发展，重点围绕锑基单能隙器件和多能隙器件结构性能开展了较为系统的研究工作，获得了一批具有现实指导意义的理论成果，基本实现项目预期研究目标，对红外热辐射谱高效管理利用的科学问题从器件结构性能层面给予了系统性回答。