Surface plasmon decorated InGaO deep-UV photodetector array for image sensing and water quality monitoring via highly effective hot electron excitation and interfacial injection

In addition to the plasmon-mediated resonant coupling mechanism, the excitation of hot electron induced by plasmon presents a promising path for developing high-performance optoelectronic devices tailored for various applications. This study introduces a sophisticated design for a solar-blind ultraviolet (UV) detector array using linear In-doped Ga₂O₃ (InGaO) modulated by platinum (Pt) nanoparticles (PtNPs). The construction of this array involves depositing a thin film of Ga₂O₃ through the plasmonenhanced chemical vapor deposition (PECVD) technique. Subsequently, PtNPs were synthesized via radio-frequency magnetron sputtering and annealing process. The performance of these highly uniform arrays is significantly enhanced owing to the generation of high-energy hot electrons. This process is facilitated by non-radiative decay processes induced by PtNPs. Notably, the array achieves maximum responsivity (R) of 353 mA/W, external quantum efficiency (EQE) of 173%, detectivity (D*) of approximately 10¹³ Jones, and photoconductive gain of 1.58. In addition, the standard deviation for photocurrent stays below 17% for more than 80% of the array units within the array. Subsequently, the application of this array extends to photon detection in the deep-UV (DUV) range. This includes critical areas such as imaging sensing and water quality monitoring. By leveraging surface plasmon coupling, the array achieves high-performance DUV photon detection. This approach enables a broad spectrum of practical applications, underscoring the significant potential of this technology for the advancement of DUV detectors.