A Self-Assembled Polymer Nanocomposite-Based Low-Voltage White Light Phototransistor With UV-Cured Synthesized LaZrOx Dielectric

Abstract

A low-cost floating film transfer (FTM) method processed gold-doped poly(3-hexylthiophene-2,5-diyl) (P3HT)-based low-voltage organic thin-film transistor (OTFT) has been fabricated and used for white light sensing. The OTFT fabrication uses a solution-processed spin casting technique for high- k dielectric growth and an FTM method for metal nanoparticle-doped organic semiconductor growth. The developed metal nanoparticle-doped organic semiconductor using FTM has the advantage of high crystallinity, self-assembly, and cost-efficient minimal wastage over other conventional film deposition techniques. The synthesized high- k dielectric film, synthesized by the low-temperature UV-cured method, offers a high dielectric capacitance of 390 nF/cm2, a low leakage current density of 0.1 μA/cm2 at -5 V, and smooth film with a surface roughness of 0.724 nm, making it appropriate for low-voltage-driven phototransistor. The device results in a photosensitivity of 248%, a high photoresponsivity of 4.41 A/W, and a specific detectivity of 3.35× 1011 Jones with a low response/recovery time of 53/85 ms at 204 μW/cm2 white light irradiation. This article explains the detailed process of device fabrication and its performance in white light sensing applications. © 1963-2012 IEEE.