Micro-Raman analysis of GaAs Schottky barrier solar cell



Gallium arsenide (GaAs) cells have been in the race with silicon single-crystal cells for the highest efficiency photovoltaic devices. The annealed, irradiated Schottky barrier (SB) solar cells were characterised using micro-Raman spectroscopy at three different regions: namely, at the (1) ohmic contact region, (2) unirradiated region and (3) irradiated region. We also present a micro-Raman study of the damage process in annealed GaAs SB solar cells bombarded by high-energy ions. A Gaussian line shape was fitted to the Raman spectra of the longitudinal optical phonon A1(LO), and parameters such as intensity, full width at half maximum (FWHM) and the area under the peak were obtained for the different annealing temperatures. Biaxial stress (σ), carrier concentration (n), depletion length (Ld), dislocation velocity (ν) and life time of the first-order optical phonon (τ) of the A1(LO) mode of the irradiated region of the samples annealed at different temperatures were calculated. Copyright © 2010 John Wiley & Sons, Ltd.