Investigation of high-quantum efficiency InGaAs/InP and InGaAs/GaAs quantum dots

Abstract

Using selective wet-chemical etching of the top barrier material of a quantum well, we have fabricated effectively buried quantum dots in the material systems InGaAs/InP and InGaAs/GaAs. The patterning is carried out on InGaAs quantum well samples masked by a high-resolution negative e-beam resist which is used as etch mask. A lateral potential well is formed due to the change of the energy barrier between the original quantum well and the surface quantum well regions. The photoluminescence shows a high efficiency as well as a shift of the luminescence signal to higher energy as the structure size is decreased. For InGaAs/InP single quantum well samples the emission of the open surface quantum well is detected. The emission of the lateral barrier regions is blue-shifted by about 24 meV compared to an unetched reference.