Copper-Doped Colloidal Semiconductor Quantum Wells for Luminescent Solar Concentrators

TL;DR

This paper introduces copper-doped colloidal quantum wells with high quantum efficiency and large absorption cross-section, enabling more effective luminescent solar concentrators for solar energy harvesting.

Contribution

First demonstration of copper doping in 2D CdSe colloidal quantum wells, achieving tunable emission and improved optical properties for solar concentrator applications.

Findings

Quantum efficiencies >43% achieved in doped CQWs

Absorption cross-section increased by an order of magnitude compared to quantum dots

Successful prototype of luminescent solar concentrator using doped CQWs

Abstract

Doping of bulk semiconductors has revealed widespread success in optoelectronic applications. In the past few decades, substantial effort has been engaged for doping at the nanoscale. Recently, doped zero-dimensional quantum dots made of semiconductor nanocrystals have been demonstrated to be promising materials for luminescent solar concentrators (LSCs) as they can be engineered for providing Stokes-shifted tunable emission in the solar spectrum. However, existing doped colloidal quantum dots suffer from moderately low quantum efficiency and intrinsically small absorption cross-section, which together fundamentally limit their effective usage. Here, we show the first account of copper doping into two-dimensional atomically flat CdSe colloidal quantum wells. Copper doping via post-synthesis partial cation exchange into 3-5 monolayers of CdSe and CdSe/CdS core-shell colloidal quantum wells (CQWs) enables Stokes-shifted, tunable dopant induced highly efficient photoluminescence emission having high quantum efficiencies (>43%), accompanied by an order of magnitude higher absorption cross-section than that of the doped quantum dots. Based on these exceptional properties, we demonstrated a flexible prototype luminescent solar concentrators using these newly synthesized doped colloidal quantum wells. These findings may open up new directions for deployment of CQWs in LSCs for advanced solar light harvesting technologies.