Thermochemistry in the system Cu–In–S at 723 K

Abstract

A thermochemical analysis is performed in the system Cu-In-S at 723 K. Free energies of In6S7, In417S583, "In2S3", Cugsjln^, and CuIn5S8 have been estimated, the numerical values (kJ/mol) of which are -1285, -97780, -481.1, -31680, and -1444. The free energy (kJ/mol) of CuInS2 is calculated from the relation G° = (-306.1 ± 54.4) + 0.50927 -1.397 10~5 T2 -0.09468T In T + 268.27-1, which is obtained from published assessed standard formation enthalpy and specific heat and entropy data. The free energy of the Cu-In melt is taken from very new literature. A consistent set of data is used for the calculation of a tentative Gibbs triangle as well as of the corresponding predominance area diagram. The Gibbs triangle is calculated with the program THERMO, the algorithm of which is given. The results are in agreement with the results of published measurements, also for the equilibria which involve the melt. The compound CuInS2, one of the possible base materials for thin film solar cells, is shown to equilibrate with most of the compounds of the system. Predictions are made how to prepare CuInS2 from Cu-In alloys and H2S/H2 gas mixtures. However, more experiments are necessary to establish the data, the experiments, and/or the results of the calculations.

Copper Indium Selenides and Related Materials for Photovoltaic Devices

“…43 A more recent experimental study of the CuInS 2 -In 2 S 3 subsection of the ternary phase field 44 found similar solid phase structures and transition temperature as those reported by Binsma, including the congruent melting of the indium-rich phase with a spinel structure and compositions around that of the compound CuIn 5 S 8 . They also found, however, an intermediate phase with a fairly narrow homogeneity range around the 62.5 mol% In 2 S 3 composition of the compound Cu 3 In 5 S 9 , which was reported to exhibit a monoclinic structure.…”

Template Synthesis of CuInS2 Nanocrystals from In2S3 Nanoplates and Their Application as Counter Electrodes in Dye-Sensitized Solar Cells

“…54 As compared to the use of Cu 2-x S precursor template, the formation of CuInS 2 from In 2 S 3 is energetically favorable. 55 For example, Lei and co-workers 56 fabricated CuInS 2 NCs by using solvothermal method on the basis of micrometer-sized spinel In 3-x S 4 templates. Recent advances in colloidal synthesis provided layered In 2 S 3 NCs including nanoplates, nanosheets and nanobelts.…”

Development of a Wide Bandgap Cell for Thin Film Tandem Solar Cells: Final Technical Report, 6 November 2003 - 5 January 2007

“…This model assumes that the S and Se incorporation in CIGSS is controlled by the kinetics of chemisorption of the chalcogen species and incorporation into the chalcopyrite lattice. This is justified by the following observations: (i) the evaporation pressure of S [11] and Se [12] is much greater than the vacuum during film growth so that the incorporation of S and Se into the film is controlled by its reaction with Cu, In, and Ga; (ii) since the reaction temperature is more than 300°C below the melting temperature of the four extremes of ternary chalcopyrites [13,14,15,16,17] the driving force to form the chalcopyrite phase from the vapor is sufficient with either S or Se [ 18,19,20]; and (iii) the growth rate is controlled by the fluxes of Cu, In, and Ga, and the relative compositions of the groups I and III species in the films match those of the fluxes. The solid lines in Figure 1 fitting the data for CIGSS samples were determined from the following simple equation derived from the kinetic model for chalcogen incorporation [10].…”