Investigation of the dielectric-modulated dual cavity organic thin-film transistor (DMDCOTFT) for label-free biomolecule identification Available to Purchase

This paper aims to propose a novel dielectric-modulated dual-cavity organic thin-film transistor (DMDCOTFT) biosensor enabling label-free, high-precision biomolecule detection with reduced sample preparation complexity, targeting medical diagnostics and environmental monitoring.

The proposed DM-DC-OTFT biosensor uses the dual cavities embedded in the gate dielectric near the source and drain regions to enhance dielectric modulation and electrostatic control. Device performance is analyzed using TCAD simulation by solving the coupled Poisson and carrier continuity equations on a finite mesh. Biomolecule detection is modeled by replacing the air-filled cavity (k = 1) with materials of varying dielectric constants and assigned charge densities representing neutral and charged species.

The drain current sensitivity for HfO₂ and Al₂O₃ rises by 458.86% and 315% for neutral biomolecules and by 116% and 62.42% for negatively charged biomolecules at V_DS = −1.5V and V_GS = −3.0V with K = 12. The device attains a maximum sensitivity of 8.76 × 10⁴ for HfO₂ and 4.4 × 10⁴ for Al₂O₃ at V_GS = −1.3V for ρ = −1 × 10¹² cm^-2.

A reference air-filled cavity (k = 1) is adopted as the standard for sensitivity evaluation to resolve inconsistencies in prior organic biosensor studies, while the proposed label-free dual-cavity design improves sensitivity and detection reliability.