کنفرانس مهندسی برق ایران

صفحه اصلی / سی و سومین کنفرانس بین المللی مهندسی برق

Fabrication and performance analysis of a ZnO phototransistor for UV detection

نویسندگان :

Ghasem Yousefi Simakani¹ ُSamaneh Hamedi²

1- دانشگاه صنعتی شیراز 2- دانشگاه صنعتی شیراز

کلمات کلیدی :

ZnO Phototransistor،Time response of phototransistor،Persistent photoconductivity،Phototransistor responsivity،Mobility

چکیده :

In this paper we present the fabrication and characterization of a ZnO phototransistor on a p-type silicon substrate with a few simple low-cost steps including cleaning and 2 sputtering steps on a pre-oxidized silicon. The p-type silicon served as the back gate, and the 300nm SiO₂ layer on the silicon was used as gate insulator. A ZnO layer as phototransistor channel was sputtered and finally, two 150nm aluminum electrode have been sputtered on the channel as drain and source electrodes. The transistor exhibited I-V characteristics over a gate voltage range of 0 to 28V, with a maximum drain-source voltage of 40V. We also measured the phototransistor's UV light responsivity, mobility, rise time, and fall time under UV illumination. A photoresponsivity of 33A/W was observed at an input optical power of 315µW/cm2 for a wavelength of 405nm, while the mobility ranged from 104 cm²/V·s to 630 cm²/V·s across the gate voltage range (0 to 28 V) with a drain-source voltage of 12V. A rise time of approximately 10s and a fall time of around 45s were recorded, demonstrating persistent photoconductivity (PPC) under UV exposure in the time-domain response. The results aligned with the expected behavior of ZnO-based photodetectors.