Photoconductivity study of Zn_xS_1-x thin film using multiple light sources

ABSTRACT

This research studied the photoconductivity of zinc sulfide thin film using multiple light sources and investigated the thermal sensing performance. Zinc sulfide with high degree sulfur vacancies was spin coated on glass and the film illuminated with light from mercury, tungsten and sodium lamp. The photo resistance value between 250 and 750 nm was obtained. High strain value obtained for the particles shows that the film is defect enriched while a steady increase in photoresistance from the UV to the visible spectrum was observed in all three lamps. However, tungsten lamp showed lower photoresistance values compared to other lamps. The photoconductivity measurements disclose a band gap of between 1.77 and 2.50 eV depending on the lamp used and reveal that the photoconductivity is controlled by boundaries of vacancies in the material. The lamps were used as photo analyzers and showed that ZnS may function as UV detectors in opto-electronic applications.

KEYWORDS:

• Zinc sulfide
• vacancies
• photoconductivity
• photo resistance
• sensors
• negative temperature coefficient

Acknowledgement

One of the authors (K. O. Olumurewa) thankfully acknowledges the Federal Government of Nigeria for providing financial support as PTDF LSS scholarship scheme (grant number-P2674883473917294).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

One of the authors (K. O. Olumurewa) thankfully acknowledges the Federal Government of Nigeria for providing financial support as PTDF LSS scholarship scheme [grant number-P2674883473917294].