Tuning optical properties of printable carbon quantum dots using near-field environment

摘要

Tuning emission properties of carbon quantum dots (CQDs) is a challenge as limited domain size of sp(2) islands in the CQDs restricts electron mobility in one dimension. The result is the formation of often blue and green light-emitting CQDs. The present manuscript depicts the transformation of CQDs into printable ink material and its utilization in fabricating films with tunable emission properties. Excitation and emission spectra of the CQDs were studied in powder form, aqueous suspension, freely suspended polyvinyl alcohol (PVA) film, printed impressions (PIs) and as thin-films respectively. Analysis of spectroscopic and microscopic data showed a substantial near-field effect in powder, CQD-embedded PVA (PVA-CQD) films and PIs. Light-responsive current-voltage characteristics in PVA-CQD films were explained in the light of interparticle-interaction induced near-field effect. (C) 2017 Elsevier Ltd. All rights reserved.