Functionalized water soluble nanomaterials and their applications in wirelessly destructible programmed flexible transient photodetectors

Abstract

Electronic systems that can respond to the user-defined circumstances from a distant location hold enormous potential in disposable devices, secured memories, restorable environmental monitoring etc. related applications which cannot be achieved by conventional silicon technology. This paper is the first demonstration of wirelessly destructible ultraviolet photodetector based on Itaconic acid functionalized water soluble ZnS on flexible polyvinyl alcohol (PVA) substrate wherein all of the device elements dissolve and/or disintegrate upon immersion in water triggered using smartphone assisted Android application. The user can wirelessly destroy the sensor anytime or the sensor can be programmed to be destroyed after performing its task. Use of graphene as both contacts as well as a transport layer enables superior photodetection while making the fabrication simple, low-cost and cleanroom free which disintegrates from the device upon dissolution in water. The fabricated transient, flexible photodetector exhibited a remarkable responsivity of 1.08 mA/W and rise time and fall times of 6.1 s and 8.23 s respectively which could be ascribed to the large electric field created at the ZnS/graphene schottky barrier. Dissolution and disintegration of the fabricated sensor demonstrate complete transience in 10 mins. The study presented here opens up numerous possibilities for applications of wireless transient photodetectors in environmental monitoring, health care, security and consumer electronics.