Blueish green photoluminescence from nitrided GaAs(100) surfaces

Optical and structural studies were made on the Si-doped (100)GaAs surfaces nitrided at a temperature between 650 degrees and 750 degrees C for 15 min in the flowing NH3 gas. The wavelength of photoluminescence (PL) spectra w ere observed to be shortened from 820 nm of the GaAs nitrided at 650 degree s C with increasing nitridation temperature. Blueish green PL with waveleng ths of approx. 490 nm and 470 nm were emitted from the nitrided surfaces at 700 degrees and 750 degrees C, respectively. Results of AES and SIMS indic ated that the surfaces are nitrided as GaAs1-xNx, (0 < x less than or equal to 1) alloy layer, and the nitrided region also tended to increase as the temperature raised. High-resolution transmission electron microscopic (HRTE M), transmission electron diffraction (TED) and energy dispersive X-ray (ED X) results showed that films peeled off from the nitrided surfaces consiste d mainly of hexagonal, wurtzite-type gallium nitride (GaN) with stacking fa ults and microtwins. (C) 1999 Elsevier Science B.V. All rights reserved.