Overcoming the efficiency limitation of semiconductor quantum dot-based light-emitting diodes

Project Information

CQWLED

Grant agreement ID: 849229

DOI

10.3030/849229

Project closed

EC signature date 11 September 2019

Start date 1 January 2020

End date 31 December 2024

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 1 498 515,00

EU contribution

€ 1 498 515,00

Coordinated by

EIDGENOESSISCHE TECHNISCHE HOCHSCHULE ZUERICH
Switzerland

Periodic Reporting for period 4 - CQWLED (Overcoming the efficiency limitation of semiconductor quantum dot-based light-emitting diodes)

Reporting period: 2024-07-01 to 2024-12-31

Summary of the context and overall objectives of the project

This project aims to understand and engineer light generation and propagation from semiconductor nanocrystals, so that more light can be directed to human eyes in their electroluminescent devices, which covert electricity to light.
It is important to society because there is high demand to use better light source with reduction of blue light that is harmful for human eyes. Light generated from semiconductor nanocrystals is not only potentially more eco-friendly and sustainable, but also generating color-pure light for different applications, significantly reduce the use of blue spectral component in light.
The overall objectives are therefore about fundamental understanding light generation within the semiconductor nanocrystals and how the geometry and electronic structure affects light propagation. Given the fundamental insights gained, we aim to design process and materials for making the light emitting devices that yield color-pure light with highest energy conversion efficiency.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

In combination with multiscale modeling and spectroscopy, we have developed theoretical framework allowing us to predict light propagation in a given semiconductor nanocrystal. We have synthesized semiconductor nanocrystals with chemistry and shape guided by our calculations. The resulting LED devices demonstrate the record-high energy conversion efficiency.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

As compared to state-of-the-art semiconductor nanocrystal light-emitting diodes, we have boosted the maximum energy conversion efficiency over 25%.
We anticipate that further optimization of our synthetic protocols would allow us to fabricate lighting devices with longer lifetime without compromising energy conversion efficiency. The use of more environmentally friendly materials would be also investigated and expected to considerably reduce the content of heavy and rare elements.

The most color-pure green light-emitting diodes using semiconductor nanocrystals