Highly Compensated GaAs Crystal Obtained by Molecular CO Doping |
| R. Bożek, K.P. Korona, G. Nowak, D. Wasik, T. Słupiński Institute of Experimental Physics, Warsaw University, Hoża 69, 00-681 Warszawa, Poland and P. Kaczor Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa, Poland |
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| GaAs:C crystal was grown by liquid encapsulated Czochralski technique with large partial pressure of CO in ambient atmosphere pCO/ptot = 0.2 and investigated using near and infrared absorption, photoluminescence, photoconductivity, photo-induced current transient spectroscopy and photo-Hall measurements. High resistivity of the crystal was found in electrical measurements (107 Ω cm, the Fermi level at 0.67 eV below conduction band at 300 K). Local vibrational mode revealed increased concentration of carbon acceptor and presence of oxygen related complexes. Photoluminescence spectra were dominated by two bands with peak energies at 1.49 eV and 0.8 eV. The near band gap emission shifts with excitation intensity up to 4 meV/decade. In photocurrent spectrum a strong photoionization band with E = 0.55 eV is observed. |
| DOI: 10.12693/APhysPolA.84.669 PACS numbers: 71.55.-i, 78.55.-m, 78.20.Jq |