Study of the composition of GaAs1-yBiy films obtained by pulsed laser deposition

Abstract

Uniaxial cold pressing was used to fabricate the GaAs1-yBiy targets with the Bi content of 1 and 22 %. From the obtained targets, pulsed laser deposition of GaAs1-yBiy thin films on the GaAs and Si substrates was carried out for the first time. We studied the composition, Raman and PL spectra of thin GaAs1-yBiy films obtained from targets with 1 and 22 % of Bi. According to the photoluminescence spectra of thin GaAs1-yBiy films on GaAs substrates, it was determined that the maximum content of Bi in the films did not exceed 2,7 %. The results obtained well correlate with the results of the energy dispersive analysis, the composition of films obtained from targets with the Bi content of 1 and 22 % - GaAs0,975 Bi-0,Bi-025 and GaAs0,973Bi0,027. It was found that the LO (GaBi) phonon mode of associated with disordering during mixing of GaAs and GaBi phases to be at a frequency of 181 cm(-1). For the thin film obtained on the Si substrate, the mode LO (GaAs) was observed that was less pronounced and shifted by 3 cm(-1) to the left, while the mode TO (GaAs), forbidden by the selection rules, had a higher intensity and its shift was of about 1 cm(-1) relative to the frequency of the mode TO (GaAs) of the thin film obtained on the GaAs substrate.