Materials World Network: Development of high-efficiency photovoltaic devices for optimal performance under a broad range of spectral illumination conditions

• Applicant: Professor Dr. Daniel M. Schaadt
• Subject Area: Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering ; Experimental Condensed Matter Physics ; Synthesis and Properties of Functional Materials
• Term: from 2013 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 239013293

We propose international collaborative effort between the University of Texas at Austin (E. T. Yu, PI) and the Clausthal University of Technology (D. M. Schaadt, German Pl) to develop materials, processing, and device technologies for high-efficiency photovoltaic devices and solar cell assemblies that can provide optimal performance under a broad range of spectral illumination conditions, as required for applications such as concentrating photovoltaics. Two main research thrusts will be pursued. First, we will investigate concepts for and band-structure engineering to realize high open circuit voltages simultaneously with high photocurrent in quantum well solar using GaAs/lnxGa1-xAs1-y-z.Sby and GaAs/InxGa1-x As1-y-z SbyNz heterostructures. These ideas will be combined with the use of sub-wavelength-scale metal/dielectric structures for longwavelength light trapping in thin-film semiconductor layers, enabling increased absorption in the quantum-well regions. Epitaxial growth and basic structural and optical materials characterization at Clausthal will be combined with heterostructure modeling and design, and device processing, and optical and electrical characterization at UT Austin to develop a comprehensive understanding of epitaxial growth, material quality, optical properties, and carrier transport processes, enabling optimization of both optical absorption and photogenerated carrier collection as required to realize the very high power conversion efficiencies predicted for such devices. Second, “metasurface" structures based on single or multiple layers of metal nanostructure arrays will be designed fabricated, and characterized at UT Austin using chemically synthesized metal nanoparticles and solution-based deposition and assembly techniques developed at Clausthal. Appropriately designed these structures will provide wavelength-selective reflectance and transmittance robust tovariations in polarization and angle of incident Iight, and are expected to enable powerful approaches for spectral splitting of sunlight in high-efficiency solar cell assemblies. The collaboration between researchers at UT Austin and the Clausthal University of Technology will be advanced via periodic visits from the home to the collaborating institution, and will build upon a strong existing collaboration between the laboratories of E. Yu at UT Austin and D. Schaadt at Clausthal.

• DFG Programme: Research Grants
• Major Instrumentation: Valved cell for antimony including flux and temperature controller controller and cables
• Instrumentation Group: 5180 Elektronen- und Ionenstrahl-Quellen und -Bearbeitungsgeräte