High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrator Application

Technical Report · Wed Sep 12 00:00:00 EDT 2012

DOI:https://doi.org/10.2172/1052851· OSTI ID:1052851

Hubbard, Seth M. ^[1]

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1. Rochester Inst. of Technology, Rochester, NY (United States)

The High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrators project seeks to provide new photovoltaic cells for Concentrator Photovoltaics (CPV) Systems with higher cell efficiency, more favorable temperature coefficients and less sensitivity to changes in spectral distribution. The main objective of this project is to provide high efficiency III-V solar cells that will reduce the overall cost per Watt for power generation using CPV systems.This work is focused both on a potential near term application, namely the use of indium arsenide (InAs) QDs to spectrally "tune" the middle (GaAs) cell of a SOA triple junction device to a more favorable effective bandgap, as well as the long term goal of demonstrating intermediate band solar cell effects. The QDs are confined within a high electric field i-region of a standard GaAs solar cell. The extended absorption spectrum (and thus enhanced short circuit current) of the QD solar cell results from the increase in the sub GaAs bandgap spectral response that is achievable as quantum dot layers are introduced into the i-region. We have grown InAs quantum dots by OMVPE technique and optimized the QD growth conditions. Arrays of up to 40 layers of strain balanced quantum dots have been experimentally demonstrated with good material quality, low residual stain and high PL intensity. Quantum dot enhanced solar cells were grown and tested under simulated one sun AM1.5 conditions. Concentrator solar cells have been grown and fabricated with 5-40 layers of QDs. Testing of these devices show the QD cells have improved efficiency compared to baseline devices without QDs. Device modeling and measurement of thermal properties were performed using Crosslight APSYS. Improvements in a triple junction solar cell with the insertion of QDs into the middle current limiting junction was shown to be as high as 29% under one sun illumination for a 10 layer stack QD enhanced triple junction solar cell. QD devices have strong potential for net gains in efficiency at high concentration.

• Research Organization: Rochester Inst. of Technology, Rochester, NY (United States); Univ. of California, Riverside, CA (United States); Computational Fluid Dynamics RC, Inc., Huntsville, AL (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• DOE Contract Number: FG36-08GO18012
• OSTI ID: 1052851
• Report Number(s): DOE/GO/18012--1
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
77 NANOSCIENCE AND NANOTECHNOLOGY
concentrator photovoltaic
epitaxy
quantum dots