UV photodetection and self-powered operation of an Au/Thorin/p-Si hybrid Schottky photodiode

Deniz A. R., Erdoğan M., Çaldıran Z., Gök G.

The European Physical Journal Plus, cilt.141, ss.1-15, 2026 (SCI-Expanded)

Özet

An Au/Thorin/p-Si/Al hybrid photodiode was fabricated and systematically investigated for UV photodetection. The

Thorin (C16H11AsN2Na2O10S2) interlayer was deposited on p-Si by spin coating. SEM, AFM, and XRD analyses revealed a

nanocrystalline film with a relatively rough surface morphology.UV–Vismeasurements yielded an optical band gap of approximately

2.95 eV, providing insight into the optical characteristics of the Thorin interlayer. Current–voltage characteristics were measured

at illumination intensities of 0–100 mW cm−2, and the main diode parameters were determined using thermionic-emission and

Norde methods. The extracted ideality factor increased from 1.55 under dark conditions to 2.41 at the highest illumination intensity,

indicating significant deviations from ideal thermionic emission behavior. The photocurrent followed a slightly superlinear

power-law dependence on illumination intensity, with α ≈ 1.18, while the photosensitivity exponent β ≈ 1.18 reflected a similar

intensity-dependent trend without uniquely identifying the underlying transport mechanism. The device exhibited its strongest

measured wavelength-dependent response at 365 nm, with a responsivity of approximately 0.08 A W−1 and an estimated specific

detectivity of approximately 2×1010 Jones, calculated using a dark-current-based shot-noise-limited approximation under the

reported measurement conditions. Responsivity, specific detectivity, and ON/OFF ratio increased with reverse bias, demonstrating

bias-dependent photodetection characteristics. A finite zero-bias photocurrent indicated the capability for self-powered photodetection.

Furthermore, the device retained its photoresponse after 30 days, with relatively limited changes in its measured characteristics.

Although its responsivity and detectivity remain below those of several recently reported UV photodetectors, the results demonstrate

the feasibility of incorporating Thorin as a chemically distinct organic interlayer in silicon-based UV photodiodes.