Combinatorial Tuning of Structural and Optoelectronic Properties in Cu Zn1−S

Abstract

Developing p-type transparent conductors (TCs) remains an outstanding challenge in optoelectronics and photovoltaics. This study uses combinatorial sputtering and spatially resolved characterization to map the full cation alloy space of Cu x Zn 1Àx S, a promising p-type TC. Formation of a metastable wurtzite alloy is observed between two cubic endpoints, leading to an electrical conductivity jump and onset of a wide-gap p-type semiconducting regime. These findings motivate further exploration of Cu x Zn 1Àx S, p-type TC development and continued application of the combinatorial materials discovery approach.

Bridging the p-type transparent conductive materials gap: synthesis approaches for disperse valence band materials

“…Cu-alloyed zinc sulfide (Cu x Zn 1−x S), the final nonoxide material covered in this review, represents a special case, as it can be synthesized either as a heterostructural alloy 101 or as a nanocomposite of Cu 2 S and ZnS, in which high conductivity stems from the Cu 2 S phase and transparency is imparted by the wide bandgap of ZnS. 102 In the case of the alloy, p-type conductivity up to 40 S cm −1 and a bandgap of 3.1 eV have been reported.…”

The Rashba Scale: Emergence of Band Anti-crossing as a Design Principle for Materials with Large Rashba Coefficient

“…This is different from an exhaustive search data-directed approach in which the discovery of materials with a given functionality is based on high-throughput computation of all (or many) possible combinations of atomic identities, composition, and structures. 32,33 This is also different from traditional machine learning, in that inverse design relies on the use of an explicitly causal physical mechanism rather than on the correlation of, say, atomistic features with the target functionality. [34][35][36] The main accomplishments of the current work are: (1) the development of the definition of the Rashba scale: all materials with larger than certain value a R have band anti-crossing, and below that threshold none has band anti-crossing; (2) the demonstration of how anticrossing bands can be identified form the atomic orbital contribution to the band structure; (3) the establishment of TRIs; (4) the inverse design of 34 strong Rashba compounds and 165 weak Rashba compounds based on the proposed theory, i.e., the anti-crossing as design principle for strong Rashba materials.…”

The role of disorder in the synthesis of metastable zinc zirconium nitrides

“…We note that in our alloy system Zn x Zr 1-x N y , the presence of a lower density hexagonal phase (BN, here) located between two higher density cubic phases (RS and BX, here) is indicative of a phenomenon in heterovalent heterostructural alloys called "negative pressure" alloys. [42,43] Additionally, these calculations use the nominal valence of the cations, namely, Zn 2+ and Zr 4+ ; we do not perform defect calculations nor vary cation oxidation states. Rigorous examination of alloy phase space would require an in-depth calculation of a temperature phase diagram, which is beyond our scope, but this approximation supports our experimental observation of a phase change from RS to BN as x increases in Zn x Zr 1-x N y .…”