Improvement of AlGaAs solar cell grown on Si substrate

The improvement of Al/sub 0.1/Ga/sub 0.9/As solar cell grown on Si substrate by metalorganic chemical vapor deposition has been described in this paper. The conversion efficiency as high as 12.9% has been obtained by employing the high growth temperature, the high annealing temperature during the growth, the long hold time at the annealing temperature and graded band emitter layer. A novel technique to reduce the stress of GaAs grown on Si is demonstrated. GaAs was grown on Si with GaSb intermediate layer, followed by the laser pulse irradiation (wavelength is 1.064 mm, the pulse width is 140 ps and pulse energy is 40 mJ/pulse). The stress of GaAs on Si with 10 laser shots is one-fourth of that before laser irradiation. The stress-relaxed AlGaAs solar cell structure on Si is proposed.