Title: Solid state photon upconversion utilizing thermally activated delayed fluorescence molecules as triplet sensitizer

Abstract

The ability to upconvert light is useful for a range of applications, from biological imaging to solar cells. But modern technologies have struggled to upconvert incoherent incident light at low intensities. In this work, we report solid state photon upconversion employing triplet-triplet exciton annihilation in an organic semiconductor, sensitized by a thermally activated-delayed fluorescence (TADF) dye. Compared to conventional phosphorescent sensitizers, the TADF dye maximizes the wavelength shift in upconversion due to its small singlet-triplet splitting. The efficiency of energy transfer from the TADF dye is 9.1%, and the conversion yield of sensitizer exciton pairs to singlet excitons in the annihilator is 1.1%. These conclusions demonstrate upconversion in solid state geometries and with non-heavy metal-based sensitizer materials.

Authors:

Wu, Tony C.; Congreve, Daniel N.; Baldo, Marc A.

Publication Date:

2015-07-20

Research Org.:

Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF)

OSTI Identifier:

1196453

Alternate Identifier(s):

OSTI ID: 1420550; OSTI ID: 1547023

Grant/Contract Number:  

FG02-07ER46474; DMR-1419807

Resource Type:

Published Article

Journal Name:

Applied Physics Letters

Additional Journal Information:

Journal Name: Applied Physics Letters Journal Volume: 107 Journal Issue: 3; Journal ID: ISSN 0003-6951

Publisher:

American Institute of Physics

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY