ELECTRICAL AND THERMOELECTRICAL PROPERTIES OF CuIn5S8-CdIn2S4 SOLID SOLUTIONS

Abstract

In the article has been investigated solid solutions of CuIn5S8-CdIn2S4 with a content of 0, 20, 40, 60, 80 and 100 mol.% CdIn2S4. The purpose of the work was to investigate the electrical and thermoelectric properties of CuIn5S8-CdIn2S4 solid solutions. The conductivity type, specific electrical conductivity, Seebeck coefficient of CuIn5S8-CdIn2S4 solid solutions were determined. The thermoelectric power of CuIn5S8-CdIn2S4 crystals was calculated. The dependence of these parameters on the CuIn5S8-CdIn2S4component composition was analyzed. To determine the Seebeck coefficient, repeatedly tested equipment and well-known methods of research using modern software were used. The conductivity type of CuIn5S8-CdIn2S4 compounds was determined by thermoelectric methods. «Digital ohmmeter Щ-34» was used to measure the resistance of the samples. The research was conducted at T≈300 K. The scientific novelty of the results is determined by the set of formulated conclusions. The main ones are that it was shown for the first time that the compounds CuIn5S8-CdIn2S4 belong to n-type semiconductors. All solid solutions turned out to be low-resistivity, with a specific resistance at room temperature ranging from 4.4∙10-4 (Ω∙m) for samples with 0 mol.% CdIn2S4 to 6∙10-5 (Ω∙m) for samples with 100 mol.% CdIn2S4. The Seebeck coefficient in the temperature range 290-360 K was 87, 157, 123, 118, 165, 166 μV/K, for samples with 100, 80, 60, 40, 20, 0 mol.% CdIn2S4, respectively. The highest value of thermoelectric power has CuIn5S8-CdIn2S4 solid solutions with a content of 60 mol.% CdIn2S4. Due to the high value of the Seebeck coefficient, these compounds are promising for the manufacture of sensitive thermal sensors. It is shown that by changing the component composition of CuIn5S8-CdIn2S4, it is possible to change the value of the Seebeck coefficient, the specific electrical conductivity, and the value of the thermoelectric power.