ZnPSe$_3$ as ultrabright indirect bandgap system with microsecond excitonic lifetimes

TL;DR

This study characterizes ZnPSe$_3$ crystals as an indirect bandgap material with strong photoluminescence and microsecond excitonic lifetimes, revealing potential for spin control in optoelectronic applications.

Contribution

It provides the first detailed optical analysis of ZnPSe$_3$, demonstrating its unique indirect bandgap with long-lived excitonic states and spin polarization capabilities.

Findings

Evidence of interband recombination with microsecond excitonic lifetimes

Reconstructed electronic band scheme for light absorption and emission

Spin polarization of electronic states observed under magnetic field

Abstract

We report an optical characterization of ZnPSe$_3$ crystals that demonstrates indirect band gap characteristics in combination with unusually strong photoluminescence. We found evidence of interband recombination from excitonic states with microsecond lifetimes. Through optical characterization, we reconstructed the electronic band scheme relevant for fundamental processes of light absorption, carrier relaxation and radiative recombination. The investigation of the radiative processes in the presence of magnetic field revealed spin polarization of fundamental electronic states. This observation opens a pathway towards controlling the spin of excitonic states in technologically relevant microsecond timescales.