Defect free visible photoluminescence from laser-generated germanium nanoparticles

TL;DR

This paper demonstrates defect-free germanium nanoparticles produced by laser etching exhibit room temperature visible photoluminescence, explained by quantum confinement effects and supported by theoretical calculations of radiative lifetime.

Contribution

It provides a detailed analysis of the origin of visible PL in Ge nanoparticles, highlighting quantum confinement and theoretical radiative lifetime calculations as key factors.

Findings

Broad visible PL observed at 2.0-2.2 eV in Ge nanoparticles

Size-dependent PL peak shift explained by quantum confinement

Theoretical radiative lifetime supports quantum recombination origin

Abstract

Origin of room temperature visible photoluminescence (PL) from defect free germanium (Ge) nanoparticles have been discussed here. The Ge nanoparticles produced by laser-induced etching technique show broad visible PL around 2.0 - 2.2 eV at room temperature. Size dependent PL peak shift in Ge nanoparticles has been explained in terms of quantum confinement. Theoretical calculations of radiative lifetime using oscillator strength, which is closely related to the size of the nanostructures, suggests that the PL is originating from a radiative recombination process in quantum confined Ge nanostructures.