Direct Laser Write‐Read‐Erase in a Functional Molecular Phase Change Material–Polymer Nanocomposite Thin Film

• Published in: Advanced optical materials 2024-04, Vol.12 (12), p.n/a
• Main Authors: Maurya, Ritesh Singh, Chaudhary, Nitin, Srujana, P., Rajput, Vinod K., Naraharisetty, Sri Ram G., Radhakrishnan, T. P.
• Format: Article
• Language: English
• Subjects: amorphous‐crystalline; Energy storage; Fluorescence; Fusible alloys; Hydrates; Information storage; Irradiation; laser write‐read‐erase; Lasers; Nanocomposites; Optical materials; Optical properties; Organic chemistry; phase change material; Phase change materials; phase transitions; Polymer films; Polymers; Storage systems; Switching; Thin films
• ISSN: 2195-1071; 2195-1071
• DOI: 10.1002/adom.202302279

Phase change materials based on organics and salt hydrates with large latent heats of transition are used extensively in energy storage systems; those based on low melting alloys exhibiting electrical/optical characteristics switching with amorphous‐crystalline (A ↔ C) transformations are of major interest in information storage devices. The direct laser write‐read‐erase is reported using a functional molecular phase change material. Facile and reversible A ↔ C transformations with concomitant switching of fluorescence emission color and intensity are demonstrated in polymer thin films doped with a diaminodicyanoquinodimethane based fluorophore using thermal operations as well as laser irradiation. In the mask‐less direct write‐erase process developed, the laser power and irradiation time are tuned to write and erase; the reading is carried out by exploiting the characteristic fluorescence signature. This work opens up a novel avenue to develop sensors and encryption systems exploiting organic molecule based optical materials encapsulated in polymer thin films. Direct laser write‐read‐erase in a functional molecular phase change material is demonstrated. The write‐erase is realized in a polymer composite thin film with embedded small molecule fluorophore, through reversible amorphous‐crystalline transformation under optimized laser irradiation, and the reading by the conspicuous fluorescence response switching.