Enthalpy of formation for Cu-Zn-Sn-S (CZTS)

TL;DR

This paper introduces an analytical method based on sputtering rates, Sigmund's theory, and the Born-Haber cycle to determine the enthalpy of formation for multinary thin film compounds like CZTS, providing a new way to assess their thermodynamic stability.

Contribution

It presents a novel analytical procedure to calculate the enthalpy of formation for multinary thin films from sputtering data, combining sputtering theory and thermodynamic cycles.

Findings

Measured enthalpy of formation for CZTS as -930±98 kJ/mol.

Found the formation reaction to be exothermic, more negative than constituent binaries.

Demonstrated the method's potential for thermodynamic analysis of complex thin films.

Abstract

Herein we report an analytical procedure to calculate the enthalpy of formation for thin film multinary compounds from sputtering rates measured during ion bombardment. The method is based on Sigmund's sputtering theory and the Born-Haber cycle. Using this procedure, an enthalpy of formation for a CZTS film of the composition Cu$_{1.9}$Zn$_{1.5}$Sn$_{0.8}$S$_4$ was measured as -930$\pm$98 kJ/mol. This value is much more negative than the sum of the enthalpies of formation for the constituent binary compounds, meaning the multinary formation reaction is predicted to be exothermic.