SBIR Phase II: Epitaxially Grown GaSb Thin Films on GaAs Substrates For Near-Field Conversion of Heat to Electricity

这个小型企业创新研究（SBIR）第二阶段项目的目标是生产用于TPV的多电池（MIM）结构的GaSb光伏器件。 目前的设备使用单电池。 MIM器件在效率和成本方面比单电池具有显著的优势。MIM器件由物理隔离在同一衬底上的许多子电池组成。 这会按比例增加输出电压并降低输出电流，从而降低内部功耗。 迄今为止，还没有出版物描述MIM Ge或GaSb MIM器件。 第一阶段计划表明，高寿命的GaSb可以外延生长在半绝缘GaAs和IR D程序表明，50个子电池MIM设备可以从外延锗半绝缘GaAs制造。 将这些元素结合起来将产生一个理想的设备。虽然Ge MIM适用于TPV，但GaSb MIM将使性能提高三到十倍。该项目更广泛的影响/商业潜力是经济有效地回收废热作为电力。 在美国，57%的发电量被废弃为废热，然而，迄今为止，还没有成功的尝试将这些热量回收为电力，而不是蒸汽用于加热目的。MTPV正在开发一种热光伏解决方案来解决这一问题，并且是使用近场倏逝波耦合的先驱，以显着增加在给定温度下从热源获得的功率密度。 MTPV发表了一份关于这一现象的明确证明，并正在使其使用商业化。 硅发射器芯片被设计成以便于形成亚微米间隙的方式从热源传递能量，目前正在铸造厂中生产，以及单电池和MIM Ge器件。 独特的外壳，需要包含这些芯片，并允许插入到一个1100摄氏度的炉设计/制造的MTPV？的设施进行发电测试。

This Small Business Innovation Research (SBIR) Phase II Project goal is to produce GaSb photovoltaic devices of multicell (MIM) construction for TPV use. Current devices use single cell. MIM devices have significant advantages over single cell in efficiency and cost. A MIM device is composed of many sub-cells physically isolated on the same substrate. This proportionally increases output voltage and decreases output current resulting in lower internal power loss. To date there have been no publications describing MIM Ge or GaSb MIM devices. The Phase I Program demonstrated that high lifetime GaSb can be epitaxially grown on semi insulating GaAs and an IR&D program demonstrated that 50 subcell MIM devices can be fabricated from epitaxial germanium on semi insulating GaAs. Combining these elements will produce an ideal device. Although the Ge MiM is suitable for TPV a GaSb MIM would give a three to tenfold improvement in performance.The broader impact/commercial potential of this project is to economically & efficiently recover waste heat as electricity. 57% of all power generated in the US is rejected as waste heat, however, to date there have been no successful attempts to recover this heat as electricity as opposed to steam for heating purposes. MTPV is developing a thermophotovoltaic solution to address this problem and is a pioneer in the use of near-field evanescent coupling to dramatically increase the power density obtainable from a heat source at a given temperature. MTPV has published a clear demonstration of this phenomenon and is engaged in commercializing its use. Silicon emitter chips designed to transfer energy from a heat source in such a manner as to facilitate the formation of a sub-micron gap are currently being produced in a foundry as well as both single cell and MIM Ge devices. The unique housing that is required to contain these chips and allow insertion into an 1100 degree C furnace is designed/ fabricated at MTPV?s facility where power generation tests are conducted.