Hybrid molecule-nanocrystal photon upconversion across the visible and near-infrared

US10386697B2 · kind B2 · utility

Assignee

• The Regents of the University of California · US

Inventors

• Christopher Bardeen · Riverside, US
• Ming L. Tang · Stanford, US
• Kerry Miller Hanson · Riverside, US
• Zhiyuan Huang · Riverside, US
• Xin Li · Shanghai, CN

Key dates

• Filing date: Jul 5, 2016
• Grant date: Aug 20, 2019
• Expiry date: Jul 5, 2036

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02E10/549
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

The ability to upconvert two low energy photons into one high energy photon has potential applications in solar cells, photodetectors and data storage. In this disclosure, CdSe and PbSe semiconductor nanocrystals are combined with molecular emitters (diphenylanthracene and rubrene) to upconvert photons in both the visible and near infrared spectral regions. Absorption of low energy photons by the nanocrystals is followed by energy transfer to the molecular triplet states, which then undergo triplet-triplet annihilation to create high energy singlet states that emit upconverted light. By using conjugated organic ligands on the nanocrystals to form an energy cascade, the upconversion process can be enhanced by up to three orders of magnitude. The use of different combinations of nanocrystals and emitters shows that this platform has great flexibility in the choice of both excitation and emission wavelengths.