Photoluminescence on high-quality AlxGa1−xAs grown by metalorganic vapor-phase epitaxy using alane bis(dimethylethylamine)

Abstract

Photoluminescence (PL) spectra are reported of initial results of AlxGa1−xAs grown by metalorganic vapor-phase epitaxy (MOVPE), using a new precursor, alane bis(dimethylethylamine), as the aluminum source. The advantage of this new precursor over other alane precursors used previously is that it is liquid at room temperature. Using this new precursor instead of trimethylaluminum (TMAl), we found a reduction by a factor 6 in carbon incorporation when it was used together with trimethylgallium (TMGa), whereas a reduction by a factor 50 was found when it was used in combination with triethylgallium (TEGa). At low excitation density the linewidth of the separate donor bound exciton (D0,X) was 2.6 meV at an Al fraction of 0.31. This is comparable with the smallest values ever reported in literature for MOVPE-grown AlxGa1−xAs with an Al fraction higher than 20%. This narrow linewidth indicates a very uniform aluminum composition.