# Copper-based semiconductor nanocrystals for optical applications

## TL;DR

Copper-based semiconductor nanocrystals have diverse optical properties and are useful in various applications like biomedicine and photovoltaics.

## Contribution

This review provides an updated overview of copper-based semiconductor nanocrystals with a focus on their optical properties and applications.

## Key findings

- Copper-based nanocrystals exhibit rich photophysics and optical versatility.
- They have potential in photovoltaics, sensing, bioimaging, and photocatalysis.
- Structure–property relationships and synthesis methods are highlighted for different nanocrystal types.

## Abstract

Copper-based semiconductor nanocrystals (SNCs) are a broad class of nanomaterials that include pnictogenides, chalcogenides, and halides. The breadth of compositions, crystal structures, and electronic properties displayed by these SNCs is reflected in their rich photophysics, which can underpin strong photon absorption capabilities, efficient (photo)luminescence, and plasmonic behavior. Because of this optical versatility, copper-based SNCs have been proposed for applications in fields such as photovoltaics, sensing, bioimaging, and photocatalysis, in some cases reaching the level of commercialization. In this review, we provide an up-to-date overview of the research on these nanomaterials with optical properties of outmost technological relevance. After a brief introduction on light-(nano)matter interaction, we individually discuss pnictogenides, chalcogenides, and halides, pinpointing structure–property relationships, identifying the most common synthesis approaches, and highlighting cases of application we consider particularly relevant or novel. Lastly, we outline outstanding challenges, with the hope of spurring the ingenuity and curiosity of researchers towards the next discoveries in this multicoloured and multifaceted field.

Copper-based semiconductor nanocrystals are versatile nanomaterials with diverse compositions, structures, morphologies, and optical properties, enabling applications in biomedicine, photocatalysis, photovoltaics, and lighting.