DocumentCode :
1438118
Title :
Substrate free GaAs photovoltaic cells on Pd-coated silicon with a 20% AM1.5 efficiency
Author :
Omnes, Franck ; Guillaume, Jean-Claude ; Nataf, Gilles ; Jager-Waldau, Gerold ; Vennegues, Philippe ; Gibart, Pierre
Author_Institution :
CNRS, Valbonne, France
Volume :
43
Issue :
11
fYear :
1996
fDate :
11/1/1996 12:00:00 AM
Firstpage :
1806
Lastpage :
1811
Abstract :
Thin-film epitaxial 2×2.5 mm2 GaAs crack free solar cells grown with metal organic vapor phase epitaxy (MOVPE) have been successfully lifted-off from their original GaAs substrate using the epitaxial lift-off (ELO) technique and Van der Waals bonded on Pd-coated silicon substrates without degrading the electrical, optical and structural properties of the devices. A 20% AM1.5 energy conversion efficiency was measured for an anti-reflection coated device, with a fill factor of 0.79, a short-circuit current density of 21.84 mA/cm2 with respect to the total area and a Voc value of 957 mV at 25°C. Electron beam induced current (EBIC) and cathodoluminescence (CL) measurements at room temperature were performed on the devices to study their structural properties. The EBIC signal image evidenced a very good homogeneous material with an EBIC contrast (C=(Imax-I)/Imax) below 1%. The variation of the penetration depth of the electron beam for a detection of the different layers of the cell gave nearly the same EBIC contrast. Only a low density of point like defects, that we assume to be structural defects, was evidenced. The CL image signal in comparison to the EBIC image didn´t give any additional results for the existence of strong nonradiative recombination centers. Cross-sectional transmission electron measurements (TEM) of the GaAs-Pd interface showed a very intimate and homogeneous bonding between the grafted layer and its host substrate
Keywords :
EBIC; III-V semiconductors; cathodoluminescence; gallium arsenide; semiconductor epitaxial layers; solar cells; transmission electron microscopy; vapour phase epitaxial growth; 20 percent; 25 C; 957 mV; AM1.5 energy conversion efficiency; EBIC; GaAs-Pd-Si; Pd-coated silicon; Van der Waals bonding; anti-reflection coating; cathodoluminescenc; cross-sectional transmission electron microscopy; electrical properties; electron beam penetration depth; epitaxial lift-off; fill factor; metal organic vapor phase epitaxy; nonradiative recombination centers; open circuit voltage; optical properties; point like defects; short-circuit current density; structural properties; substrate free GaAs photovoltaic cell; thin-film crack free solar cell; Bonding; Current measurement; Electron beams; Epitaxial growth; Gallium arsenide; Optical films; Photovoltaic cells; Silicon; Substrates; Temperature measurement;
fLanguage :
English
Journal_Title :
Electron Devices, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9383
Type :
jour
DOI :
10.1109/16.543011
Filename :
543011
Link To Document :
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