Only point defects are created in the silicon lattice due to a low radiation dose. It is possible to regenerate these defects at very low temperatures. By higher radiation doses the point defects tend to create defect clusters, dislocation loops or even dislocation loop networks. These defects are much more stable than the point defects [2]. A temperature rise of about 400°C is necessary to regenerate such more complex defects. In the first experiments a low radiation dose of 1.1010 cm-2 2MeV protons was applied to boron doped n+/p silicon photovoltaic cells. The equivalent 1 MeV electron dose is about 5.1013 cm-2, i.e. a half year dose in Clarke orbit. Radiation fluence was under 1.106 cm-2 s-1 to avoid the thermal effect. A semiconductor GaAlAs diode laser with output power up to 10 mW CW was used for annealing. This laser emits on the 830 nm wavelength. A laser beam with a diameter of 100 fim was scanned over the whole area of the 4 X 4 mm2 samples with a velocity up to 2 cm/s. From the above data it can easily be calculated that the temperature rise in the centre of the laser beam was well under 1°C. In these experiments mostly only short circuit current was investigated under AM 1.5 conditions. Short circuit current of the radiation-damaged samples was compared before and after laser annealing. It was found out that in optimum annealing conditions photovoltaic cells regain about 50% of the short circuit current which was lost by radiation damage (Fig. 1). From the results it is evident that in this experiment laser annealing is a nonthermal phenomenon. In recent reports injection-enhanced annealing has been described, which enables nonthermal annealing of the radiation damage in InP and even in silicon. Yamaguchi [3] reports that forward bias and photon-induced injection annealing is possible in InP. According to Barnes [4] forward bias injection annealing was possible also in radiation-damaged silicon solar cells. Results mentioned in this paper seem to be due to photoinjection annealing. Laser Regeneration System Important progress in the field of GaAlAs semiconductor diode laser arrays is reported by Spectra Diode Laboratories Inc. Laser arrays with output power of 5.4 W CW and 11 W quasi-CW were realized at SDL [5]. In the near future GaAlAs diode laser
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