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Crystal structure, electrical, and optical properties of Cu 3 In 7 Te 12 ordered defect semiconducting compound
Author(s) -
Guedez E.,
Rincón C.,
Wasim S. M.,
Delgado G. E.,
Marcano G.,
SánchezPérez G.
Publication year - 2017
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201700087
Subject(s) - tetragonal crystal system , materials science , acceptor , band gap , absorption edge , condensed matter physics , effective mass (spring–mass system) , ternary operation , electron mobility , semiconductor , impurity , charge carrier , thermoelectric effect , hall effect , scattering , crystal structure , electrical resistivity and conductivity , crystallography , chemistry , optoelectronics , optics , physics , organic chemistry , quantum mechanics , computer science , programming language , thermodynamics
CuInTe 2 chalcopyrite semiconductor and the ordered defect compounds of the Cu 2 Te–In 2 Te 3 pseudo‐binary system have recently emerged as suitable candidates for thermoelectric applications. In this article, the crystal structure, optical, and electrical properties of Cu 3 In 7 Te 12 , a member of this ternary system, have been studied. It was established that this material crystallizes in a tetragonal structure with space group P4 ¯ 2 c . The analysis of the optical absorption spectrum near the fundamental absorption edge shows that the energy gap is direct and the band gap varies from 1.030 to 0.952 eV between 10 and 300 K. From the analysis of electrical data, it was found that above 160 K, the electrical conduction is due to the activation of a shallow acceptor level of about 10 meV, and the value of the hole‐effective mass is m h = (1.18 ± 0.35) m e . In the temperature range from 160 to 130 K, variable range hopping (VRH) mechanism of Mott‐type in the impurity band is observed. At high temperatures, the mobility is explained by taking into account the scattering mechanism of the charge carriers by donor–acceptor defect pairs, ionized and neutral impurities, acoustic and non‐polar optical phonons. In the low temperature region, the mobility data can be explained by an expression related to Mott law for VRH conductivity.