Optical study of ZnP2 nanoparticles in zeolite Na–X

Nanoparticles of the II–V semiconductor (ZnP2) were prepared and investigated. ZnP2 nanoparticles were incorporated into zeolite Na–X matrix. Absorption, diffuse reflection (DR) and photoluminescence (PL) spectra of ZnP2 nanoparticles were measured at the temperature of 77 K. Five bands B1–B5 are observed in both the DR and PL spectra demonstrating the blue shift from the line of free exciton in bulk crystal. We attribute the B1–B5 bands to five stable nanoparticles with size less than the size of zeolite Na–X supercage. We observed Stokes shift of the PL bands with respect to the absorption bands. This dependence of this Stokes shift on the particle size is nonmonotonic.