<title>Electrical and optical studies of NTD GaAs crystals</title>

Abstract

The electrical properties and photoluminescence spectra ofLEC gallium arsenide crystals after neutron transmutation doping (NTD) have been investigated as function ofstarting material properties, irradiation dose and thermal to fast neutron fluence ratio.The residual carbon acceptors interact with radiation induced defects (RD) in neutron irradiated GaAs crystals and form nonradiative recombination centers, which are stable up to 700 °C.

High‐resolution photoinduced transient spectroscopy of defect centres in semi‐insulating GaP

“…Oxygen is a dominant residual impurity in GaP crystals grown by LEC method of the Zn Ga shallow acceptor and Sn Ga shallow donor equal to 69.7 meV and 72 meV, respectively [8]. It should be noted that both zinc and tin are known to be background impurities frequently occurring in GaP crystals grown by the LEC method [2,17,21].The shallow traps TB2 (85 meV), TB3 (95 meV) and TA7 (110 meV) are likely to be attributed to shallow donors formed by residual silicon atoms in the gallium sublattice, tellurium atoms in the phosphorus sublattice and sulphur atoms in the phosphorus sublattice, the ionization energies of which are 85 meV, 93 meV and 105 meV, respectively [8,9,18]. On the grounds of the reported experimental data [10][11][12]15,…”

“…It has been shown that a very high-resistivity (>10 7 Ωcm) of undoped GaP wafers can be achieved by defect engineering methods involving high temperature annealing in the phosphorus (P) vapour atmosphere [2,3]. The aim of this paper is to give an in-depth insight into the defect structure of SI GaP obtained in this way.…”