Nanophotonic enhanced two-photon excited photoluminescence of perovskite quantum dots

TL;DR

This study demonstrates that nanophotonic structures significantly enhance two-photon photoluminescence in perovskite quantum dots, reducing the required irradiance for multi-photon processes and enabling advances in optoelectronic applications.

Contribution

The paper introduces a method of using silicon photonic crystal slabs to enhance two-photon excitation in perovskite quantum dots, lowering the irradiance needed for multi-photon processes.

Findings

Over one order of magnitude enhancement of photoluminescence

Relation of enhancement to near-field effects on nanostructured silicon

Potential for low-threshold lasing and biomedical imaging

Abstract

All-inorganic CsPbBr3 perovskite colloidal quantum dots have recently emerged as promising material for a variety of optoelectronic applications, among others for multi-photon-pumped lasing. Nevertheless, high irradiance levels are generally required for such multi-photon processes. One strategy to enhance the multi-photon absorption is taking advantage of high local light intensities using photonic nanostructures. Here, we investigate two-photon-excited photoluminescence of CsPbBr3 perovskite quantum dots on a silicon photonic crystal slab. By systematic excitation of optical resonances using a pulsed near-infrared laser beam, we observe an enhancement of two-photon-pumped photoluminescence by more than one order of magnitude when comparing to using a bulk silicon film. Experimental and numerical analyses allow relating these findings to near-field enhancement effects on the nanostructured silicon surface. The results reveal a promising approach for significant decreasing the required irradiance levels for multi-photon processes being of advantage in applications like low-threshold lasing, biomedical imaging, lighting and solar energy.