PHOTOLUMINESCENCE FROM ALGAAS-GAAS SINGLE QUANTUM-WELLS GROWN ON VARIOUSLY ORIENTED GAAS SUBSTRATES BY MBE

Photoluminescence (PL) measurements at low temperatures have been carried out for AlGaAs-GaAs single quantum well (SQW) structures grown on (100), (110), (111)B, (311)A and (311)B GaAs substrates by MBE. A mirror smooth surface was obtained under each optimal growth condition except for (111)B and (110) samples. The (110) surface is cloudy due to the columnar growth. PL results suggest that the height of column is in the order of 10 nm. The film on the (111)B surface consists of a lot of trigonal pyramids, which give a rather broad line width of PL peaks from a SQW compared with the (100) sample. The high optical quality for both (311)A and (311)B SQW's, which is comparable to that for (100) SQW's, is achieved in optimal growth conditions. PL study determines the heavy-hole effective mass of about 0. 5 m//0 for the left bracket 311 right bracket direction.