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

• Antragsteller: Professor Dr. Daniel M. Schaadt
• Fachliche Zuordnung: Elektronische Halbleiter, Bauelemente und Schaltungen, Integrierte Systeme, Sensorik, Theoretische Elektrotechnik ; Experimentelle Physik der kondensierten Materie ; Herstellung und Eigenschaften von Funktionsmaterialien
• Förderung: Förderung von 2013 bis 2017
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 239013293

• Erstellungsjahr: 2017

Zusammenfassung der Projektergebnisse

We proposed an 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 were pursued. First, we investigated concepts for band-structure engineering to realize high open circuit voltages simultaneously with high photocurrent in quantum dot/well solar using group III-As based heterostructures. Initial work was focused on the system GaAs/lnxGa1-xAs quantum dot/wells and later extended to first simulations and experiments on GaAs/AlAs/In xGa1-x As1-y-z SbyNz. These ideas were combined with the use of sub-wavelength-scale metal/dielectric structures for long wavelength light trapping in thin-film semiconductor layers, enabling increased absorption in the quantum-well regions. Simulation, epitaxial growth and basic structural and optical materials characterization at Clausthal was 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 were designed, fabricated, and characterized using chemically synthesized metal nanoparticles and solutionbased deposition and assembly techniques. Additional support was introduced in this field through a collaboration with Prof. Shabat from the Islamic University of Gaza. We could show in joint collaborative effort,that appropriately designed structures are able to increase the efficiency of group III quantum well structures in the infra-red region, and enable powerful approaches for spectral splitting of sunlight in high-efficiency solar cell assemblies. The collaboration between researchers at UT Austin, the Clausthal University of Technology and the Islamic University of Gaza was advanced via periodic visits from the home to the collaborating institution, and has led to a strong existing collaboration between the laboratories. It has setup the basis for a follow up project were the above mentioned concepts and ideas can be explored and advanced in further detail.

Projektbezogene Publikationen (Auswahl)

• “Influence of hole shape/size on the growth of siteselective quantum dots”, Nanoscale Res. Lett. 8, 504 (2013)
  C. J. Mayer, M. F. Helfrich, and D. M. Schaadt
  
• “Light trapping in thin-film solar cells via scattering by nanostructured antireflection coatings”, J. Appl. Phys. 114, 044310 (2013)
  X. H. Li, P. C. Li, D. Z. Hu, D. M. Schaadt, and E. T. Yu
  
• “Measurement of indium concentration profiles and segregation efficiencies from highangle annular dark field-scanning transmission electron microscopy images”, Ultramicroscopy 131, 1 (2013)
  Thorsten Mehrtens, Knut Müller, Marco Schowalter, Dongzhi Hu, Daniel M Schaadt, Andreas Rosenauer
  
• “Angular dependence of light trapping in In0.3Ga0.7As/GaAs quantum-well solar cells”, J. Appl. Phys. 115, 044303 (2014)
  X. H. Li, P. C. Li, D. Z. Hu, D. M. Schaadt, and E. T. Yu
  
• “Integrated optical nanostructures for wide-angle antireflection and light trapping in III/V solar cells”, Photovoltaic Specialist Conference 40, 2238 (2014)
  X. H. Li, P. C. Li, D. Z. Hu, D. M. Schaadt, Ch. Stender, C. O. McPheeters, R. Tatavarti, K. Sablon, and E. T. Yu
  
• “Design and analysis of multilayer waveguides containing nanoparticles for solar cells”, Solar Energy 137, 409 (2016)
  Mohammed M Shabat, Dena M El-Amassi, Daniel M Schaadt
  
• “Metamaterial-Silicon Anti-reflection Waveguide Model for Solar Cells”, Optics for Solar Energy, SoW2C. 2 (2016)
  Houria Hamouche, Mohammed Shabat, Daniel Schaadt
  
• “Wide-angle and wavelength-independent perfect absorption at metamaterial surfaces”, R. Rep. Phys. 68 (2), 725 (2016)
  M. F. Ubeid, M. M. Shabat, and D. M. Schaadt
  
• “Multilayer solar cell waveguide structures containing metamaterials”, Superlattices and Microstructures 101, 633 (2017)
  Houria Hamouche, Mohammed M. Shabat, Daniel M. Schaadt