Le Journal de Physique IV 03 (1993) C5-115-C5-118
Optical properties of GaAs/AlGaAs quantum dots realized by implantation induced intermixingF.E. PRINS1, F. ADLER1, G. LEHR1, S.Yu. NIKITIN2, H. SCHWEIZER1 and G.W. SMITH3
1 4. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart 80, Germany
2 Minsk Radioengineering Institut, Microelectronics Department, 6 P. Brovki Str., 220600, Republic Byelarus (C.I.S.)
3 DRA Malvern, St. Andrews Rd, Malvern, Worcs, WR14 3PS, G.B.
GaAs/AlGaAs quantum dots with diameter down to 70 nm have been realized by implantation induced intermixing. Photoluminescence studies demonstrate a high optical quality. From the systematic small blue shift of the dot luminescence with dot diameter it is shown that the dots reveal a steep radial potential and that the blue shift is caused by quantization. The increase of relative quantum efficiency of the dots with decreasing diameter can be explained by a model which takes the graded shape of the potential and the carrier capture from the barrier into account. Time-resolved measurement yield short carrier lifetimes in the dots. With decreasing dot diameter an increasing decay time and a slowed carrier cooling is observed.
© EDP Sciences 1993