High-Performance Ti3C2Tx MXene-InP Side-Illuminated Schottky Photodetector: Theoretical design and performance enhancement beyond Graphene-Based devices

This comprehensive theoretical study investigates a novel MXene-based side-illuminated Schottky photodetector (SIMS-PD) integrated on an InP waveguide platform for telecommunication wavelengths. Building on our previous work with graphene-based devices achieving responsivities up to 1.76 A/W, we propose a Ti 3 C 2 T x MXene double-layer structure that theoretically demonstrates superior performance metrics. Through electromagnetic modeling using Lumerical MODE and COMSOL Multiphysics, we predict a responsivity of 2.31 A/W at 1.55 μm—representing a 31% improvement over trilayer graphene devices. The MXene structure exhibits ultra-low dark current (5 × 10 − 1⁶ A), exceptional detectivity (2.1 × 1013 Jones), and 42 GHz bandwidth capability. These enhanced properties arise from MXene’s unique combination of metallic conductivity (8,500 S/cm), tunable work function (4.1–4.8 eV), and strong optical absorption coefficient (3.8 × 105 cm − 1). Comparative analysis reveals MXene’s advantages in terms of solution processability, environmental stability, and voltage tunability (Δμ = 0.8 eV) over graphene counterparts. The proposed device architecture features optimized field confinement at the MXene-InP interface with 85% modal overlap, achieving quantum efficiency of 0.69. This work establishes MXene as a promising alternative to graphene for next-generation integrated photodetectors, particularly for applications in optical communications, quantum technologies, and high-sensitivity sensing systems.