VISIBLE LIGHT EMISSION FROM NITROGEN IMPLANTED GaAs

The visible light emission from nitrogen implanted GaAs by applying reverse bias has been observed for the first time in our laboratory.Samples were prepared with following procedures: zino diffusion, nitrogen implantation (at 450°C), annealed under H2 atmosphere at temperature from 540°G up to 600-650°C by applying the uncoating technique, and finally meases were performed by conventional techniques.A special measurement system has been established to measure the spectra of the weak light which can be observed in darkness with the naked eye. Preliminary stability tests shows that the lifetime of the continuous visible light emission from the exposed meases is more than 16 hours under reverse bias conditions.The peak energy of the emitted light shift to higher energy as the excitation intensity increased. The peak shift is ≥15meV/10 mA. This means that the emission band is caused by donor-acceptor pair recombination. Therefore, it is proposed that the optical emission of photon energies above GaAs band gap energies is caused by the recombination of the ion pair of NAs. (isoelectronic trap)-free hole or other ion pairs in the P-region.The detailed mechanism still remains to be clarified in the future.