Controlling Nanogap Quantum Dot Photoconductivity through Optoelectronic Trap Manipulation

TL;DR

This paper demonstrates optoelectronic techniques to manipulate charge traps in nanogap quantum dot devices, leading to more reproducible and tunable photoconductivity by controlling impurities and defects.

Contribution

It introduces a unified model and experimental methods for controlling trap states in nanocrystal devices, enhancing reproducibility and device performance.

Findings

Optoelectronic methods can alter solid-state charge trap populations.

A unified model explains and predicts trap-related photoconductivity behavior.

Trap manipulation improves device reproducibility and tunability.

Abstract

Nanoscale devices are being extensively studied for their tunable electronic and optical properties, but the influence of impurities and defects is amplified at these length scales and can lead to poorly understood variations in characteristics of semiconducting materials. By performing a large ensemble of photoconductivity measurements in nanogaps bridged by core-shell CdSe/ZnS semiconductor nanocrystals, we discover optoelectronic methods for affecting solid-state charge trap populations. We introduce a model that unifies previous work and transforms the problem of irreproducibility in nanocrystal electronic properties into a reproducible and robust photocurrent response due to trap state manipulation. Because traps dominate many physical processes, these findings may lead to improved performance and device tunability for various nanoscale applications through the control and optimization of impurities and defects.