Specific heat, debye temperature, and belated properties of chalcopyrite semiconducting compounds CuGaSe2, CuGaTe2, and CuInTe2

Abstract

The specific heat Cv of the ternary semiconducting compounds CuGaSe2, CuGaTe2, and CuInTe2 is determined experimentally in a temperature region within 2 and 30 K. From the results the Debye temperatures and standard entropies are calculated. By dividing Cv into a Debye and two Einstein contributions the approximate shape of the low frequency phonon modes is estimated.

Temperature variation of optical energy gap values of the compound CuGaTe2

“…4 The lattice thermal expansion in this material over the temperature range 80 to 650K was determined by Bodnar and Orlova. 5 The specific heat and Debye temperature were reported by Bohmhammel et al 6 Hörig et al 7 investigated the electrical and optical properties using single crystal samples of this material. Neumann et al 8 studied the temperature dependence of the Hall coefficient of epitaxial layers of CuGaTe 2 on GaAs substrates.…”

“…In order to use these data to calculate C e and C h , it is necessary to know values of α L v, m e , and m h in Eq. (6) and Eq. (7).…”

“…(3) the term in U is the dilation contribution, while the term in V is the electron-phonon contribution. Thus, the dilation term can be used to give (dE g /dT) 1 , and the electron-phonon term to give (dE g /dT) 2 , (dE g /dT) 1 = -U (5) (dE g /dT) 2 = -Vθ 2 /2T 2 cosech 2 (θ/2T) (6) It is seen from the above equations that (dE g /dT) 2 varies to some extent with T, while (dE g /dT) l is independent of T. It is seen from Fig. 4 that in the range 150-300K, the variation of E g with T is, within the limits of experimental errors, linear.…”

Heat capacity and thermodynamic functions of the CuAlS2 semiconductor in the temperature range from 80 to 300 K

“…Investigations of C P for CuAlTe 2 have been carried out in the temperature range from 300 to 500 K [5], for CuGaS 2 : 300-600 K [6], 1.2 -40 K [7], for CuGaSe 2 : 2 -30 K [8], for CuGaTe 2 : 2 -30 K [8], 300 -500 K [6], for CuInS 2 : 1 -293 K [9], 300 -500 K [6], for CuInSe 2 : 1 -40 K [9], 300 -500 K [6], for CuInTe 2 : 2 -30 K [8], 1 -40 K [9], 300 -500 K [6], for AgGaS 2 : 1.2 -40 K [7], for AgGaSe 2 : 300 -500 K [10,11], for AgGaTe 2 : 1-40 K [9], and for AgInS 2 : 300-500 K [10,11]. Low-temperature heat capacity and thermodynamic properties of natural and sintered chalcopyrite CuFeS 2 at 5-300 K have been measured in [12].…”

Enhanced thermoelectric performance via the solid solution formation: The case of pseudobinary alloy (Cu2Te)(Ga2Te3)3 upon Sb substitution for Cu

“…K is the Boltzmann's constant, C is a constant, vs is the velocity of sound (2.28×10 3 m/s), 40,41 which is assumed not varying with composition, Ω is the volume of the unit cell, and c is the relative concentration of pure material (c>0.5 in the present solid solutions).…”