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

fYear

2009

fDate

7-12 June 2009

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 Â± 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;

fLanguage

English

Publisher

ieee

Conference_Titel

Photovoltaic Specialists Conference (PVSC), 2009 34th IEEE

Conference_Location

Philadelphia, PA

ISSN

0160-8371

Print_ISBN

978-1-4244-2949-3

Electronic_ISBN

0160-8371

Type

conf

DOI

10.1109/PVSC.2009.5411190

Filename

5411190