Cathodoluminescence study of InGaAs/GaAs quantum dot structures formed on the tetrahedral-shaped recesses on GaAs (111)B substrates

InGaAs/GaAs quantum dot (QD) structures grown in tetrahedral-shaped recesses (TSR) etched into GaAs (111)B substrates are studied by means of cathodoluminescence (CL). Two main features are observed in the CL spectra. The lower energetic peak can be assigned to QDs in the bottom of the TSRs, while the higher energetic one corresponds to the quantum wells (QWs) formed at the sides of the TSRs. This can be confirmed by spatially resolved CL imaging. The behavior of QD and QW luminescence is studied by temperature and electron beam intensity dependence of CL. We will show that the formation of the QDs is strongly dependent on the size and the spacing of the TSRs. (C) 1998 American Institute of Physics.