Title :
Thermal and spectroscopic characterization of quantum dot-enhanced solar cells
Author :
Gardner, J. ; Albers, E. ; Bailey, C.G. ; Hubbard, S. ; Raffaelle, R.
Author_Institution :
NanoPower Res. Labs., Rochester Inst. of Technol., Rochester, NY, USA
Abstract :
Three characterization methods are discussed for InAs/GaAs quantum dot (QD)-enhanced GaAs solar cells. Photoreflectance (PR) and electroluminescence (EL) measurements yield seven QD-related transitions between 1.1 and 1.4 eV. The PR feature attributed to bulk GaAs at 1.42 eV is analyzed to extract an electric field strength in the solar cell depletion region of 43 ± 1 kV/cm2. Temperature coefficients are measured for open-circuit voltage and short-circuit current under AM1.5D illumination from devices with zero, five, and 20 layers of QDs, and improved temperature stability is observed in the QD-enhanced devices. Lastly, the saturation current activation energy for two samples is extracted, and the results are presented as evidence of bandgap tuning.
Keywords :
electroluminescence; gallium arsenide; photoreflectance; semiconductor quantum dots; solar cells; AM1.5D illumination; InAs-GaAs; QD-enhanced devices; QD-related transitions; bandgap tuning; depletion region; electric field strength; electroluminescence measurements; electron volt energy 1.1 eV to 1.4 eV; electron volt energy 1.42 eV; open-circuit voltage; photoreflectance measurements; quantum dot-enhanced solar cells; saturation current activation energy; short-circuit current; spectroscopic characterization; temperature coefficients; temperature stability; thermal characterization; Current measurement; Electroluminescence; Gallium arsenide; Lighting; Photovoltaic cells; Quantum dots; Spectroscopy; Stability; Temperature measurement; Voltage measurement;
Conference_Titel :
Photovoltaic Specialists Conference (PVSC), 2009 34th IEEE
Conference_Location :
Philadelphia, PA
Print_ISBN :
978-1-4244-2949-3
Electronic_ISBN :
0160-8371
DOI :
10.1109/PVSC.2009.5411190
