Converting infrared light into broadband visible light at high efficiency using lanthanide-sensitized oxides

US9601647B2 · kind B2 · utility

Assignee

• The Chinese University of Hong Kong · CN

Inventors

• Jianfang Wang · Hangzhou City, CN
• Junxin Wang · Hefei, CN
• Tian Ming · Cambridge, US

Key dates

• Filing date: May 15, 2014
• Grant date: Mar 21, 2017
• Expiry date: May 15, 2034

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02E10/52

Abstract

The present invention includes upconversion materials such as lanthanide-sensitized oxides that are useful for converting low-energy photons into high-energy photons. Because silicon-based solar cells have an intrinsic optical band-gap of 1.1 eV, low-energy photons having a wavelength longer than 1100 nm, e.g., infrared photons, cannot be absorbed by the solar cell and used for photovoltaic energy conversion. Only those photons that have an energy equal to or greater than the solar cell's band gap, e.g., visible photons, can be absorbed and used for photovoltaic energy conversion. The oxides described herein transform photons having an energy less than the energy of a solar cell's band gap into photons having an energy equal to or greater than the energy of the band gap. When these oxides are incorporated into a solar cell, they provide more photons for photovoltaic energy conversion than otherwise would be available in their absence. Nearly 10% of the infrared photons incident on these oxides are upconverted into visible photons. This upconversion efficiency is more than twice as large as the upconversion efficiency for NaYF4-based upconversion materials. The solar radiation energ…