GROWTH OF DIRECT BANDGAP GAINP QUANTUM DOTS ON GAP SUBSTRATES

GaInP has a direct bandgap for In concentrations higher than approxima tely 30%, and the band-lineup between GaInP and GaP is type-II for In concentrations less than 60%. Therefore, in order to use GaInP as the active light-emitting layer in an optoelectronic device grown on GaP, the strain induced by the lattice mismatch between GaInP and GaP has t o be somehow managed such that formation of crystal defects is suppres sed. One method is to grow the layer thinner than the critical thickne ss. Another method that recently received much attention is to grow st rain-induced Stranski-Krastanov islands (sometimes referred to as self -assembled quantum dots). Small droplets of highly lattice-mismatched materials have been embedded into single crystals without generating d efects such as threading dislocations and stacking faults using this m ethod. We have grown a series of GaInP/GaP layers by metalorganic chem ical vapor deposition and have studied the light emission from them. O rdered GaInP islands were found to be responsible for the light emissi on. We present the light emission characteristics of these ordered GaI nP/GaP islands, and their dependence on various growth parameters.