Combinatorial Tuning of Structural and Optoelectronic Properties in CuxZn1-xS

P-type transparent conductors (TCs) are important enabling materials for optoelectronics and photovoltaics, but their performance still lags behind n-type counterparts. Recently, semiconductor Cu_xZn_1−xS has demonstrated potential as a p-type TC, but it remains unclear how properties vary with composition. Here, we investigate Cu_xZn_1−xS across the entire alloy space (0 ≤ x ≤ 1) using combinatorial sputtering and high-throughput characterization. First, we find a metastable wurtzite alloy at an intermediate composition between cubic endpoint compounds, contrasting with solid solutions or cubic composites (ZnS:Cu_yS) from the literature. Second, structural transformations correlate with shifts in hole conductivity and absorption; specifically, conductivity increases at the wurtzite phase transformation (x ≈ 0.19). Third, conductivity and optical transparency are optimized within a “TC regime” of 0.10 < x < 0.40. This investigation reaffirms Cu_xZn_1−xS as a promising, tunable, multifunctional semiconductor alloy, provides new insight into composition-dependent evolution of structure and properties, and informs future research into device applications.