H. Kalisch et al., MOVPE OF ZNMGSSE HETEROSTRUCTURES FOR OPTICALLY PUMPED BLUE-GREEN LASERS, Journal of electronic materials, 26(10), 1997, pp. 1256-1260
We report on the growth of ZnMgSSe/ZnSSe/ZnSe heterostructures in a lo
w pressure metalorganic vapor phase epitaxy (MOVPE) system at 400 hPa
and a growth temperature of 330 degrees C, The precursor combination w
as dimethylzinc(triethylamine adduct), ditertiarybutylselenium, ditert
iarybutylsulphur, and bismethylcyclopentadienylmagnesium. This combina
tion allows the reproducible adjustment of the alloy composition in a
wide range (currently up to 40% S and 32% Mg) maintaining high crystal
homogeneity and almost lattice matched growth. Undoped separate confi
nement heterostructure (SCH) lasers with ZnMgSSe cladding and ZnSSe gu
iding layers were deposited on GaBs substrates. X-ray diffraction (rec
iprocal space mapping), photoluminescence (PL) at 14-300K, PL excitati
on, and optical pumping experiments were performed. The quantum wells
show a high luminescence efficiency up to room temperature. Optical pu
mping experiments were carried out at various temperatures (77,300-375
K) and excitation densities using a nitrogen laser. The lasing thresho
ld could be determined to be less than 20 kW/cm(2) at 77K, and even ro
om temperature: lasing was observed at an excitation density which was
below 200 kW/cm(2).