Optical Properties of ZnP2 Nanoparticles in Zeolite

TL;DR

This study reports the first synthesis and optical characterization of ZnP2 semiconductor nanoparticles embedded in zeolite Na-X, revealing size-dependent spectral shifts and stable nanocluster formation at cryogenic temperatures.

Contribution

It introduces a novel method for preparing ZnP2 nanoparticles within zeolite supercages and provides detailed optical spectra analysis at 77 K.

Findings

Observation of five distinct absorption and PL bands indicating stable nanoclusters.

Blue shift in spectra compared to bulk crystal due to quantum confinement.

Nonmonotonic Stokes shift behavior explained by competing shifts.

Abstract

We report that for the first time the nanoparticles of II-V semiconductor (ZnP2) were prepared and studied. ZnP2 nanoparticles were prepared by incorporation into zeolite Na-X matrix. Absorption, diffuse reflection (DR) and photoluminescence (PL) spectra of the ZnP2 nanoclusters incorporated into the supercages of zeolite Na-X were measured at the temperature 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 some stable nanoclusters with size less than the size of zeolite Na-X supercage. We observed Stokes shift of the PL bands from the respective absorption bands. The nonmonotonic character of its dependence on the cluster size can be explained as the result of competition of the Frank-Condon shift and the shift due to electronic relaxation.