SBIR Phase I: Dry Epitaxial Lift-off for High Efficiency Solar Cells

SBIR 第一阶段：高效太阳能电池的干式外延剥离

• 批准号: 1215626
• 负责人: John Farah
• 金额: $ 15万
• 依托单位: OptiCOMP Networks
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1215626&HistoricalAwards=false
• 关键词: SBIR; Phase; Dry; Epitaxial; Lift

This Small Business Innovation Research Phase I project develops a method of lifting-off an epitaxially grown high-efficiency ( 30%) triple-junction III-V solar cell from a Ge or GaAs wafer onto a polyimide substrate. A high-coefficient of thermal expansion (CTE) polyimide wafer is used to induce a crack that propagates parallel to the surface at the epi/wafer interface, due to the mismatch between the coefficients of thermal expansion, as the wafer is cooled down below room temperature. The lift-off happens in a fraction of a second and no expensive ion implantation or slow chemical etching of a sacrificial layer is needed. The epi-layer is attached to a low-cost flexible polyimide substrate having a thickness between 25 and 100 microns which serves as the permanent carrier of the solar cell. Inverted and non-inverted cells can be lifted off using this technique. The base substrate can be reused to grow another epi-layer and the cycle repeated. For these devices, the cost of substrate materials is about 40% of the cost of the finished cell. This process will result in savings of raw materials and grinding and etching costs, up to a total savings of 30% of the cost of the cell. The broader impact/commercial potential of this project will be to develop a method to transfer epitaxially-grown device layers from semiconductor wafers to inexpensive polymeric substrates to create high-performance flexible circuits. The application of this technology goes beyond photovoltaics (PV). Space-grade as well as terrestrial high-efficiency PV cells and modules can be made lighter, flexible, and less expensive when this process is integrated into the manufacturing sequence of established suppliers. Additionally, when the thinned cell is transferred to a metallic substrate, the reduced thickness improves performance of terrestrial concentrating PV systems. Once this method is demonstrated, we will leverage our relationships with major high-efficiency solar cell manufacturers to negotiate licensing of the technology for their applications.

这个小型企业创新研究阶段I项目开发了一种从GE或GAAS晶片上升高外延高效率（30％）三型晶胞的方法，将其从GE或GAAS晶胞上升级到Polyirimide sistrate。 由于热膨胀系数之间的不匹配，由于晶圆在室温以下冷却时，因此使用了高热膨胀（CTE）聚酰亚胺晶片来诱导裂纹，该裂纹在Epi/Wefer界面在Epi/Wefer界面平行传播。升降机发生在一秒钟的一小部分，不需要昂贵的离子植入或需要缓慢的牺牲层化学蚀刻。 ePi层连接到具有25至100微米之间的厚度的低成本柔性聚酰亚胺基板，该基材用作太阳能电池的永久载体。可以使用此技术将倒置和无向导的细胞解除。 可以将碱基底物重新使用以生长另一个层状层并重复循环。 对于这些设备，基材材料的成本约为成品单元成本的40％。 此过程将节省原材料，磨削和蚀刻成本，总节省的总成本的30％。该项目的更广泛的影响/商业潜力将是开发一种方法，将外延生长的设备层从半导体晶片转移到廉价的聚合物基板上，以创建高性能的柔性电路。 该技术的应用超出了光伏（PV）。当将该过程集成到已建立的供应商的制造序列中时，空间级以及陆地高效的PV单元和模块可以变得更轻，灵活和便宜。 此外，当将稀释的细胞转移到金属底物上时，厚度的减小会改善陆地浓缩PV系统的性能。 一旦证明了这种方法，我们将利用与主要高效太阳能电池制造商的关系来协商该技术的应用程序。