Accurate Wavelength Tracking by Exciton Spin Mixing

Research output: Contribution to journalResearch articleContributedpeer-review



Wavelength-discriminating systems typically consist of heavy benchtop-based instruments, comprising diffractive optics, moving parts, and adjacent detectors. For simple wavelength measurements, such as lab-on-chip light source calibration or laser wavelength tracking, which do not require polychromatic analysis and cannot handle bulky spectroscopy instruments, lightweight, easy-to-process, and flexible single-pixel devices are attracting increasing attention. Here, a device is proposed for monotonously transforming wavelength information into the time domain with room-temperature phosphorescence at the heart of its functionality, which demonstrates a resolution down to 1 nm and below. It is solution-processed from a single host–guest system comprising organic room-temperature phosphors and colloidal quantum dots. The share of excited triplet states within the photoluminescent layer is dependent on the excitation wavelength and determines the afterglow intensity of the film, which is tracked by a simple photodetector. Finally, an all-organic thin-film wavelength sensor and two applications are demonstrated where this novel measurement concept successfully replaces a full spectrometer.


Original languageEnglish
Article number2205015
JournalAdvanced materials
Issue number38
Publication statusPublished - 22 Sept 2022

External IDs

Scopus 85136855354
ORCID /0000-0002-4112-6991/work/142254745



  • colloidal quantum dots, dual-state Forster resonance energy transfer, organic room-temperature phosphorescence, organic wavelength sensors, transient photocurrent

Library keywords