D N Bose
Articles written in Bulletin of Materials Science
Volume 17 Issue 4 August 1994 pp 347-354
Deep level transient spectroscopy (DLTS) was carried out on single crystals of the layered chalcogenide p-GaTe using Schottky barriers parallel and perpendicular to the layer planes to study the possible anisotropy of the defect levels. Deep levels with the same energies (0·28 eV and 0·42–0·45eV) have been found in both directions with concentrations ranging from 1013cm−3 to 1014 cm−3 and capture cross-sections from 10−15cm2 to 10−17cm2. The difference in the spectra obtained from the two planes and the possible reason for the deep level energies being independent of crystal orientation are discussed.
Volume 23 Issue 3 June 2000 pp 207-209
Volume 28 Issue 7 December 2005 pp 647-650 Semiconductors
Semi-insulating < 111 > ZnTe prepared by In doping during Bridgman growth was found to have a resistivity of 5.74 × 107 ohm-cm, the highest reported so far in ZnTe, with hole concentration of 2.4 × 109/cm3 and hole mobility of 46 cm2/V.s at 300 K. The optical band gap was 2.06 eV at 293 K compared with 2.26 eV for undoped semiconducting ZnTe. Thermally stimulated current (TSC) studies revealed 2 trap levels at depths of 202–222 meV and 412–419 meV, respectively. Photoluminescence (PL) studies at 10 K showed strong peaks at 1.37 eV and 1.03 eV with a weak shoulder at 1.43 eV. Short anneal for 3 min at 250°C led to conversion to a 𝑝-type material with resistivity, 14.5 ohm-cm, indicating metastable behaviour. Raman studies carried out on undoped and In-doped samples showed small but significant differences. Possible models for semi-insulating behaviour and meta-stability are proposed.
Volume 42 | Issue 5
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