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

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. [ABSTRACT FROM AUTHOR]