Photomodulated reflectance spectroscopy on gallium arsenide and gallium indium arsenide

Abstract

There are many different means to characterize the semiconductor materials. Optical methods are of great significance because they are contactless, non-destructive and unambiguous. Photomodulated reflectance (PR) is one of such techniques.

In this thesis, I describe the optical setup used for PR and a custom LabVIEW program to control the data acquisition. In addition to this, this program also analyzes input data and plots spectra in real time.

PR spectra of GaAs and GalnAs were measured to verify proper function of the optics, electronics, and custom program. The experiment confirmed PR spectra could be measured from these samples at room temperature. The energy gaps measured were in the 1.405 to 1.43 eV range.