SIZE QUANTIZATION AND ZERO-DIMENSIONAL EFFECTS IN SELF-ASSEMBLED SEMICONDUCTOR QUANTUM DOTS

In this paper we discuss size quantization effects in InAs self assemb led quantum dots deposited by molecular beam epitaxy (MBE) on (100) Ga As. The quantum dot size measurements are performed by transmission el ectron microscopy while the energy levels from the same samples are me asured by capacitance, photoluminescence, photovoltage and electrolumi nescence techniques. Size quantization effects are observed, however v ariations in the quantum dot shapes, composition fluctuations and non uniform size distribution, which are deposition dependent prevent comp lete and accurate quantification of these effects. Through infrared ab sorption measurements together with capacitance measurements, the zero dimensional character of the quantum dots and ''the atomic like'' she ll structure of the electronic levels in the quantum dots are establis hed.