Enhanced photocurrent in solution processed electronically coupled CdSe nanocrystals thin films

TL;DR

This paper demonstrates that solution-processed CdSe nanocrystal films, treated with ethanedithiol and annealed, exhibit significantly enhanced photocurrent, making them promising for high-performance optoelectronic devices.

Contribution

It introduces a simple low-cost method to fabricate highly continuous CdSe nanocrystal films with improved electron coupling and photocurrent through specific post-deposition treatments.

Findings

Ethanedithiol treatment enhances electron coupling between nanocrystals.

Photocurrent increases by four orders of magnitude after treatment.

Thermal annealing causes redshift and broadening of absorption features.

Abstract

We have demonstrated the fabrication of highly continuous and smooth CdSe semiconductor films containing self-assembled nanocrystals (NCs) using a simple, low cost solution-processed deposition technique. The impact of thermal annealing and ethanedithiol (EDT) treatment on oleate capped CdSe NCs films is illustrated. Post deposition EDT treatment enhances strong electron coupling between NCs by reducing the inter-particle distance, which enhances four orders of magnitude of photocurrent in the pn-device. Mild thermal annealing of NC films cause large redshift and significant broadening. Our findings suggest that NCs with short-range organic ligands are suitable for high-performance Thin-Film-Transistors and next generation high-efficiency photovoltaics.