GOALI:Cooperative Integration of High Efficiency Multijunction Solar Cell Structures

这项研究的目标是开发一种多结太阳能电池，它有可能超过目前41.6%的太阳能-电能转换效率记录。该电池采用串联锗/砷化镓/磷化铟镓结构，受顶部两个电池产生的电流限制。该方法是将应变层超晶格集成到这两个细胞中，以减小带隙。由此产生的由顶部和中间电池产生的电流可能会显著增加，而电压只会小幅下降，这应该会提高多结光伏器件的效率。这项工作将对光伏器件和应变层超晶格的科学产生影响。自第一个多结PV器件演示以来，将太阳光谱的光吸收扩展到传统砷化镓太阳能电池之外的能力一直是一个长期存在的问题。所提出的工作将扩展该吸收区域，同时保持不同材料的晶格匹配，从而延长载流子寿命。应变层超晶格在其他应用中也有广泛的适用性，例如用于高频通信和传感的光电探测器和光调制器。光伏材料具有提供清洁和可再生能源的潜力。该项目将培养学生在半导体行业中使用的一些技能，如生长、制造、表征和器件建模。这将包括本科生、少数民族学生、高中生和教师的参与。

The objective of this research is to develop a multijunction solar cell which has the potential to exceed the current record solar-to-electric energy conversion efficiency of 41.6%. This cell uses a tandem germanium/gallium arsenide/indium gallium phosphide structure, which is limited by the current generated in the top two cells. The approach is to integrate strained layer superlattices into both of these cells in order to reduce the bandgap. The resulting potentially significant increase in the current generated by the top and middle cells with only a small decrease in voltage, should improve the efficiency of the multijunction photovoltaic device.This work will impact the science of photovoltaic devices and strained layer superlattices. The ability to extend the optical absorption of the solar spectrum beyond that of conventional GaAs solar cells has been a long-standing problem since the demonstration of the first multijunction PV device. The proposed work will extend this absorption region while maintaining lattice matching of dissimilar materials, and thus carrier lifetimes. Strained layer superlattices have wide applicability in other applications as well, such as photodetectors and optical modulators for high frequency communications and sensing.Photovoltaic materials have the potential to provide a clean and renewable energy source. The project will train students in a number of skills used in the semiconductor industry such as growth, fabrication, characterization and device modeling. This will include the participation of undergraduate, minority students, and high school students and teachers.