Dielectrically Modulated Label Free Metal Controlled Organic Thin Film Transistor for Biosensing Applications

Abstract

In this work, a novel structure of Dielectrically Modulated Organic Thin Film Transistor (OTFT) for biosensing applications is presented. The proposed device uses lateral metal contacts and an implanted metal with work function of 5.7 eV inside the organic material; as such it is being named as Metal Controlled Organic Thin Film Transistor (MC-OTFT). The performed 2D simulation study has revealed that the proposed MC-OTFT shows significantly higher sensitivity for different dielectric constants and their related charge densities. Besides, the calibrated simulation study has shown that the change in ON current ( I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> sensing factor calculated for V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</sub> =- 1.5V, V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">GS</sub> =-3 V) in MC-OTFT is significantly higher (max. of 44.40 times for neutral, 44.55 times for charged biomolecule at ρ = - 1×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> ). In addition, a considerable enhancement in sensitivity at low temperatures has been observed. The proposed device therefore offers a huge potential for biosensing applications.