Electric transport properties of two-dimensional electron gases near to InAs quantum dots.

Author(s)

Ivan Ramos Pagnossin

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Física (IF/SBI)
• Defense date: 2004-04-29

Examining board members

Euzi Conceicao Fernandes da Silva; Lucy Vitoria Credidio Assali; Marcelo Nelson Paez Carreno

• Advisor: Euzi Conceicao Fernandes da Silva

Abstract

In this work, systematic Shubnikov-de Haas and Hall measurements as a function of the sample illumination time were used to investigate the transport properties of a two-dimensional electron gas (2DEG) confined in GaAs/InGaAs quantum wells and close to InAs quantum-dots placed in the GaAs top barrier. We did not observe any expressive degradation of the electronic mobility due to the insertion of them in the heterostructure. However, we observed a different change of the quantum mobility of the occupied subbands from sample to sample, which was attributed to the accumulation of mechanical strain in the InAs layer. The behavior of the quantum and transport mobilities are discussed in the context of the local modulation of the band edges by the InAs layer. (AU)