Boron Site Distribution in Doped GaAs

Abstract

The lattice site distribution of boron in doped, melt-grown GaAs was studied by means of photoluminescence and local vibrational mode spectroscopy. The investigated samples were cut from nominally Si or Ge doped crystals grown under stoichiometric or Ga rich conditions. In GaAs : Si boron behaves like an amphoteric dopant. The formation of the antisite, B As , is favoured by the growth from a Ga rich melt. In Ge doped GaAs, on the other hand, only the isovalent boron defect, B Ga , was observed. Apart from infrared absorption spectra measured by the established Fourier transform technique the B As -related radiative recombination and the local Raman modes of the boron species are presented. These results demonstrate, that photoluminescence and near infrared Raman spectroscopy are viable tools for the detection of substitutionally incorporated boron in GaAs.

How silicon and boron dopants govern the cryogenic scintillation properties of N-type GaAs

“…Table II shows that although all samples are n-type, NB is higher than Ne, and in some cases considerably higher. This is in agreement with evidence that most of the boron resides on isoelectronic gallium sites and that the boron acceptor emission arises from a smaller fraction on arsenic acceptor sites [14].…”

Growth and characterization of GaAs crystals produced by the VCz method without boric oxide encapsulation

“…Here, the p-type conductivity is caused by a different acceptor, because in case of LEC growth, the carbon content in the crystal is well adjustable, but using a boric oxide encapsulation, a high concentration of boron is incorporated. With increasing arsenic deficiency in the melt, boron is not to be found anymore only at Ga site, but also at As site, acting as an acceptor [27]. Additionally, the concentration of the mid-gap donor EL2 decreases too, resulting finally in the observed p-type conductivity.…”

Defect distribution in boron-reduced GaAs crystals grown by vapour-pressure-controlled Czochralski technique

“…As the donor concentration increases, the 1.441 eV transition cannot be resolved anymore. Besides the increasing Si Ga donor concentration, the broadening of the band edge luminescence could also be ascribed to an increasing concentration of the compensating Si As À acceptor at 1.485 eV [32,33].…”