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Tuning 2D Light Upconversion Emission by Modulating Phonon Relaxation
Author(s) -
Kim Bum Jin,
Lim Soo Yeong,
Cho Youngho,
Nam Sang Hwan,
Suh Yung Doug,
Park Chan Ryang,
Kim Hyung Min
Publication year - 2017
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.201700782
Subject(s) - photon upconversion , materials science , infrared , optoelectronics , fourier transform infrared spectroscopy , photon , substrate (aquarium) , photonics , optics , doping , physics , oceanography , geology
The photonic upconversion in rare earth atoms is widely used to convert “invisible” near infrared photons to “visible” photons with continuous wave light. By using a patterned substrate, upconversion become a route for creating new information‐incorporating security codes. The amount of information in the cipher increases in proportion to the number of emission colors as well as the pattern structure. Subsequently, changing the chemical composition of upconversion phosphors on 2 D substrates is required to manufacture information‐rich upconversion cryptography. In this study, we exploited temperature‐controlled thermal reaction on upconversion films deposited on a quartz substrate to prepare security information codes. Multiple color emission was generated from upconversion films as the result of inserting high‐frequency molecular oscillators into the film structures. Fourier‐transform infrared (FTIR) and time‐resolved study corroborated the mechanism of spectral variation of upconversion films.