3D photoluminescent nanostructures containing quantum dots fabricated by two-photon polymerization : influence of quantum dots on the spatial resolution of laser writing

Abstract

Quantum dots (QDs) films or layers are extensively used for various photonic and electronic applications since recent decades. Three-dimensional (3D) nanostructures are the elegant fashion in micro-optics, microfluidics, biomedicine, and imaging. In particular, 3D photoluminescent nanostructures play an important role in detection and sensing as well as emitting systems. In this work, 3D photoluminescent structures containing QDs with feature sizes down to 80 nm are fabricated via two-photon polymerization-based direct laser writing. The photoluminescent images and emission spectra show strong local emission of blue, green, and red light from the polymer micro and nanostructures. The influence of the QDs, laser power, and writing scan speed on the resolution of the as-prepared structures is also investigated. It turns out that the presence of QDs increases the lateral resolution where the feature size of polymer lines can reach 75 nm in 3D. This promising result paves the way for the integration of single nano-emitters with a fine control of their spatial positioning in some nanophotonic devices.