Materials World Network: Design, fabrication and characterization of advanced heterojunction photovoltaic devices based on enhanced scattering into lateral optical paths

我们建议加州大学圣地亚哥分校（E。Yu，PI）和德国卡尔斯鲁厄大学（D. Schaadt）开发用于高效光伏器件的GaAs/InGaAs和GaAs/InGaNAs量子阱（QW）和量子点（QD）p-i-n异质结构首先，要实现超过60%的功率转换效率量子阱和量子点层在p-i-n光电二极管将用于吸收太阳光谱中能量低于GaAs p和n电极层带隙的入射光子。第二，薄的多个QW和/或QD层中的高效吸收将通过金属或电介质纳米结构的集成来实现，以将量子阱/点波长的入射光子散射到由于InGaAs相对于GaAs的更高折射率而被光学限制的横向传播路径中。研究将最终通过衬底去除和双面处理开发出非常薄的器件结构。这种结构将提供入射光子到横向光学限制的传播路径中的非常有效的耦合，并且使得能够结合到柔性或弯曲表面上。在这项合作中，卡尔斯鲁厄的研究人员将专注于材料生长和优化，而UCSD的研究人员将专注于器件设计、加工和表征。

We propose an international collaborative effort between the University of California, San Diego (E. Yu, PI) and the University of Karlsruhe in Germany (D. Schaadt) to develop GaAs/InGaAs and GaAs/InGaNAs quantum-well (QW) and quantum-dot (QD) p-i-n heterostructures for high-efficiency photovoltaic devices First, to achieve power conversion efficiencies in excess of 60%, quantum-well and quantum-dot layers in the intrinsic region of a p-i-n photodiode will be used for absorption of incident photons in the solar spectrum at energies below the band gap of the GaAs p and n electrode layers. Second, highly efficient absorption in thin multiple QW and/or QD layers will be achieved by integration of metal or dielectric nanostructures to scatter incident photons at quantum-well/dot wavelengths into lateral propagation paths that are optically confined due to the higher refractive index of InGaAs relative to GaAs. Research will culminate in the development of a very thin device structure via substrate removal and double-sided processing. This structure will provide very efficient coupling of incident photons into lateral optically confined propagation paths, and enable bonding onto flexible or curved surfaces. In this collaborative effort, researchers at Karlsruhe will focus on material growth and optimization, while UCSD researchers will focus on device design, processing, and characterization.