Self-powered visible transparent $$\mathrm{Cu}/{\mathrm{Zn}}_{\left(1-x\right)}{\mathrm{Sn}}_{\left(x\right)}\mathrm{O}$$ Schottky-based ultraviolet photosensors fabricated via DC magnetron sputtering

Abstract

AbstractVisible transparent $$\mathrm{Cu}/\mathrm{n}-\mathrm{ZnO}$$ Cu / n - ZnO and $$\mathrm{Cu}/{\mathrm{Zn}}_{\left(1-x\right)}{\mathrm{Sn}}_{\left(x\right)}O\left(x=0.14\right) \mathrm{TZO},$$ Cu / Zn 1 - x Sn x O x = 0.14 TZO , Schottky junctions were successfully fabricated on ITO-coated glass substrates via direct current magnetron reactive sputtering method. The structural, morphological, optical, and electrical properties were thoroughly investigated. The polycrystalline nature of the samples was confirmed by XRD studies. FESEM images validate the changes in surface morphology after doping and annealing, and AFM analysis confirmed the variation in surface roughness. The electrical analysis reveals the presence of a Schottky barrier in the fabricated devices. In dark condition, three-order rectification ratio was observed. A two-order increase in leakage current was also observed after illuminating 365 nm UV light of power 60 µW/cm2. The figures of merits of sensors, such as responsivity, detectivity, response speed, and linear dynamic range, were thoroughly investigated. The fabricated sensor had a responsivity of about 07.80 mA/W and a detectivity of 1.39 × 1011 Jones. At zero bias, the sensor also demonstrated a transient photocurrent response of approximately 783 ms for rise and 876 ms for fall. Similarly, 33.70 dB of linear dynamic range was observed. These findings suggests that Cu/TZO Schottky diodes could be useful for self-powered, visible transparent UV photosensors in next-generation optoelectronic devices.