Zinc cadmium phosphide arsenide (Zn-Cd-P-As) is a quaternary system of group II (IUPAC group 12) and group V (IUPAC group 15) elements. Many of the inorganic compounds in the system are II-V semiconductor materials. The quaternary system of II3V2 compounds, (Zn1−xCdx)3(P1−yAsy)2, has been shown to allow solid solution continuously over the whole compositional range. This material system and its subsets have applications in electronics, optoelectronics, including photovoltaics, and thermoelectrics.