Photovoltaic Effect and Space Charge Limited Current Analysis in TlGaTe2 Crystals
A.F. Qasrawia,b, T.R. Yaseena, B. Eghbariya and N.M. Gasanlyc
aDepartment of Physics, Arab-American University, Jenin, West Bank, Palestine
bGroup of Physics, Faculty of Engineering, Atilim University, 06836 Ankara, Turkey
cDepartment of Physics, Middle East Technical University, 06531 Ankara, Turkey
Received: December 8, 2010
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Anisotropic space charge limited current density analysis and photovoltaic effect in TlGaTe2 single crystals has been investigated. It is shown that, above 330 K, the crystal exhibits intrinsic and extrinsic type of conductivity along (c-axis) and perpendicular (a-axis) to the crystal's axis, respectively. The current density (J) is found to be space charge limited. It is proportional to the square and three halves power of voltage (V) along the a- and c-axis, respectively. Along the a-axis and at sufficiently low electric field values, the activation energy of the current density is found to depend on the one half power of electric field. At high electric fields, the activation energy is field invariant. This behavior is found to be due to the Pool-Frenkel effect and due to a trap set located at 0.26 eV, respectively. Along the c-axis the crystal is observed to operate under the Child-Langmuir space charge limited regime. TlGaTe2 crystals are found to exhibit photovoltaic properties. The open circuit photovoltage is recorded as a function of illumination intensity at room temperature.
DOI: 10.12693/APhysPolA.122.152
PACS numbers: 72.20.-i, 72.20.Ht, 72.40.+w