A broadband and self-driven light sensing optoelectronic device based on a plasmonic MXene-based Ni 2 O 3– X –polymer/TiO 2 heterostructure

A cost-effective and scalable optoelectronic device based on an MXene-based Ni 2 O 3− X –P1HP (poly(1H-pyrrole))/TiO 2 nanocomposite was fabricated through a facile synthetic strategy involving the incorporation of this composite on additional P1HP seeding layer. The enhanced MXene-based Ni 2 O 3− X –P1HP/TiO 2 /P1HP optoelectronic performance originates from the synergistic integration of multiple semiconductor components with oxygen-deficient Ni 2 O 3− X , whose plasmonic characteristics and defect-rich electronic structure promote efficient light harvesting and charge transport. Under ultraviolet illumination, the fabricated device achieved a maximum responsivity of 2.0 mA W –1 and a specific detectivity of 0.18 × 10 10 Jones. Remarkably, the device maintained substantial photoactivity at lower photon energies (1.6 eV; ∼730 nm), delivering a responsivity of 1.5 mA W –1 and a detectivity of 0.13 × 10 10 Jones, thereby showing efficient operation within the visible–near-infrared spectral region. Morphological investigations revealed the formation of semispherical and rod-like nanostructures with characteristic dimensions of approximately 100 nm. Optical analysis further demonstrated a narrowed band gap of ∼1.48 eV, facilitating enhanced optical absorption across a broad spectral range. In addition, the oxygen-vacancy-rich Ni 2 O 3− X phase introduced localized defect states that promoted hot-carrier generation and suppressed charge recombination. Collectively, these structural and electronic features enable efficient photon harvesting, rapid charge-transfer kinetics, and improved carrier separation, highlighting the potential of this low-cost MXene-based architecture for next-generation optoelectronic sensing applications.