Direct Visualization of UV-Light on Polymer Composite Films Consisting of Light Emitting Organic Micro Rods and Polydimethylsiloxane

Misuk Kim; Jiyoun Kim; Hyeonwoo Kim; Incheol Jung; Hojae Kwak; Gil Sun Lee; Young Jun Na; Young Ki Hong; Dong Hyuk Park; Kyu-Tae Lee

doi:10.3390/polym14091846

Direct Visualization of UV-Light on Polymer Composite Films Consisting of Light Emitting Organic Micro Rods and Polydimethylsiloxane

Polymers (Basel). 2022 Apr 30;14(9):1846. doi: 10.3390/polym14091846.

Authors

Misuk Kim¹, Jiyoun Kim², Hyeonwoo Kim¹, Incheol Jung¹, Hojae Kwak¹, Gil Sun Lee³, Young Jun Na⁴, Young Ki Hong^{4

5}, Dong Hyuk Park², Kyu-Tae Lee¹

Affiliations

¹ Department of Physics, Inha University, Incheon 22212, Korea.
² Department of Chemical Engineering, Program in Biomedical Science and Engineering, Inha University, Incheon 22212, Korea.
³ Department of General Education, Kookmin University, Seoul 02707, Korea.
⁴ Department of Physics, Gyeongsang National University, Jinju 52828, Korea.
⁵ Research Institute of Natural Science, Gyeongsang National University, Jinju 52828, Korea.

Abstract

We experimentally demonstrate the direct visualization of ultraviolet (UV) light using flexible polymer composite films consisting of crystalline organic tris-(8-hydroxyquinoline) aluminum (Alq3) micro-rods and polydimethylsiloxane (PDMS). The representative organic mono-molecule Alq3, which is a core material of organic light-emitting diodes, was used to detect light in the invisible UV region and visualize photoluminescence (PL). Alq3 shows absorption in the UV region and light-emitting characteristics in the green region, making it an optimal material for UV visualization because of its large Stokes transition. Crystalline Alq3 micro-rods were fabricated in a deionized water solution through a sequential process of reprecipitation and self-assembly. Highly bright photoluminescence was observed on the highly crystalline Alq3 micro-rods under UV light excitation, indicating that the crystalline structures of Alq3 molecules affect the visible emission decay of excitons. The Alq3 micro-rods were manufactured as flexible polymer composite films using a PDMS solution to observe UV photodetector characteristics according to UV intensity, and it was confirmed that the intensity of the fine UV light reaching the earth's surface can be visualized by making use of this UV photodetector.

Keywords: Alq3; PDMS; micro-rods; polymer composite films; ultraviolet; visualization.

Grants and funding

This work was supported in part by the Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Science, ICT (NRF-2021R1A2C201419). This work was supported in part by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (No. 2020R1A4A1017915). This work was also supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education (No. 2021R1I1A305950911).