Seminar 8.1.15

  Physical Electronics Dept.

You are invited to attend a lecture

By

Yoav Livneh

(M.Sc. student under supervision of Prof. Yossi Rosenwaks, Dr. Philip Klipstein,

School of Electrical Engineering, Tel-Aviv University, Tel-Aviv 69978, Israel)

On the subject:

Band Structure Calculation and Analysis

of Antimonide Based Type-II Superlattices

Superlattices are a kind of quantum structure, made up of alternating thin layers of two materials. By changing the layer widths of the individual materials in the superlattice, we can control the optical and electrical properties of the material (bandgap engineering). In recent years, InAs/GaSb type-II superlattices (T2SLs) have become a very attractive potential sensing material in photonic devices used for infrared sensing and imaging.

This work presents a new and effective model for the prediction of T2SL band structure and absorption spectra, based on the k.p method, including a novel approach to the effect of the interfaces between the two individual materials. The main difference between this method and other k.p based methods is in the operator ordering, and in the use of delta-function like interface potentials. The model has reduced the number of fitting parameters to only six, all of which can be deduced empirically.

Calculation results show very good agreement with measurements on over 30 samples grown by Molecular Beam Epitaxy, both in the band gaps and the absorption spectra.

Thursday, 8 January 2015 at 09:30

Room 101, Software Eng. Build.