Title :
Short circuit current enhancement of GaAs solar cells using strain compensated InAs quantum dots
Author :
Hubbard, Seth M. ; Bailey, Christopher G. ; Cress, Cory D. ; Polly, Stephen ; Clark, Jeremy ; Forbes, David V. ; Raffaelle, Ryne P. ; Bailey, Sheila G. ; Wilt, David M.
Author_Institution :
NanoPower Research Laboratory, Rochester Institute of Technology, 85 Lomb Memorial Drive, NY 14623, USA
Abstract :
Tensile strain compensation (SC) layers were introduced into GaAs p-i-n solar cells grown with a five-stack of InAs quantum dots (QDs) within the i-region. The effects of strain within stacked layers of InAs quantum dots (QDs) were investigated using high resolution x-ray diffraction (HRXRD). Analysis of the HRXRD data shows that the average lattice strain is minimized for the optimal SC thickness. One sun air mass zero illuminated current-voltage curves show that SC results in improved conversion efficiency and reduced dark current when compared to uncompensated devices. The strain compensated 5-layer QD solar cell shows a 0.9 mA/cm2 increase in short circuit current compared to a baseline GaAs cell. Quantum efficiency measurements show this additional current results from photo-generated carriers within the quantum confined material.
Keywords :
Capacitive sensors; Gallium arsenide; Lattices; PIN photodiodes; Photovoltaic cells; Quantum dots; Short circuit currents; Sun; Tensile strain; X-ray diffraction;
Conference_Titel :
Photovoltaic Specialists Conference, 2008. PVSC '08. 33rd IEEE
Conference_Location :
San Diego, CA, USA
Print_ISBN :
978-1-4244-1640-0
Electronic_ISBN :
0160-8371
DOI :
10.1109/PVSC.2008.4922600
