The field effect of photoluminescence due to excitons bound to N atom pairs was investigated in uniformly doped and atomic-layer doped samples grown onto (001) GaAs substrates. The intensities of excitonic photoluminescence lines, due to distant N-atom pairs, decreased much more rapidly than those from closer pairs when the electric field was increased. In addition, photoluminescence due to the nearest-neighbor pairs in atomic-layer doped samples exhibited much more stable characteristics than those of uniformly doped samples in an applied electric field. This stability was observed only when the electric field was applied in the [110] or [¯110] directions. This anomalous field effect could be explained by considering electron-trapping to iso-electric N traps, modulated by the electric field.

Field Effect of Photoluminescence from Excitons Bound to Nitrogen Atom Pairs in GaAs. K.Onomitsu, A.Kawaharazuka, T.Okabe, T.Makimoto, H.Saito, Y.Horikoshi: Japanese Journal of Applied Physics - 1, 2002, 41[9], 5503-6