Off-stoichiometric semiconductors Cu1.33+xZn1.33-xIn1.33Se4 (x = 0, 0.1, 0.2 and 0.3): Synthesis, structure, and thermal and electrical properties.

The synthesis, structure, and temperature dependent thermal and electrical properties of off-stoichiometric polycrystalline modified zinc blende quaternary chalcogenides Cu 1.33+x Zn 1.33-x In 1.33 Se 4 , where x ​= ​0, 0.1, 0.2 and 0.3, are investigated. Temperature-dependent electrical properties reveal these compositions to be semiconductors with alteration of the carrier concentration and electrical transport via stoichiometric variation. The thermal conductivity is low for all specimens and intrinsic to these materials. First principles calculations are also reported in establishing a fundamental investigation that illustrates the large variation in stoichiometry that is possible in these materials. This stoichiometric variation results in the observed variation of the transport properties. The results presented reveal fundamental structure-property relationships in these quaternary chalcogenides, and provides a basis for further research into the viability for large stoichiometric variation in other materials that are of interest for technological applications. Synthesis, structure, transport properties, and theoretical calculations on off-stoichiometric variants of modified zinc blende quaternary chalcogenides are reported for the first time. The data for Cu 1.33+x Zn 1.33-x In 1.33 Se 4 indicate an intrinsically low thermal conductivity with a relatively low Debye temperature, while electrical properties are dramatically altered with variation in stoichiometry. [Display omitted] • Off-stoichiometric modified zinc-blende Cu1.33 ​+ ​xZn1.33-xIn1.33Se4 were synthesized, and their structure and temperature-dependent transport properties investigated. • First-principles calculations were reported in order to investigate the phase stability of these materials. • Stoichiometric variation lead to dramatic alteration in electrical transport properties, while the thermal conductivity is intrinsically low for all compositions. • Low temperature specific heat measurements reveal a Debye temperature of 223 ​K. [ABSTRACT FROM AUTHOR]