P-doped Mg x Zn 1Ϫx Te alloys ͑0рxр0.28͒ are characterized using room-temperature electrical, optical, and photoelectric measurements. The electrical properties ͑hole concentration and mobility͒ indicate an increasing compensation with the increase of Mg content. The donor impurities are attributed to P. The optical absorption spectrum exhibits a peak situated at 1.06 eV, independent of composition. Supportive evidence is obtained for the assignment of this peak to electronic transitions in the shallow P acceptor level originating from the spin-orbit band. The perturbations in the local potential lead to a broadening of the absorption peak and to the appearance of density-of-states tails at the edges of the principal bands. The spectral response of indium surface barriers on undoped and P-doped crystals is investigated. It is found that P doping leads to a lowering of the barrier height and to a shift in the high-energy edge of the spectral response toward lower energies. The latter is attributed to the presence of a thin insulating interfacial layer and a high density of interface states in the P-doped contacts. It is suggested that P has a role in determining the characteristics of the interface.