ZnS microspheres-based photoconductor for UV light-sensing applications

• Published in: Chemical physics letters Vol. 763; p. 138162
• Main Authors: Kumar, Arun, Kumar, Manjeet, Bhatt, Vishwa, Kim, Deasung, Mukherjee, Samrat, Yun, Ju-Hyung, Choubey, Ravi Kant
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 16.01.2021
• Subjects: Hydrothermal method; Photoconductor; ZnS microspheres; Photoconductor; ZnS microspheres; Hydrothermal method
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2020.138162

[Display omitted] •Physical properties are sensitive to the morphology of the nanostructured ZnS.•ZnS microspheres have been synthesized by using one-step hydrothermal synthesis.•Spherical nanostructured morphology is favorable for efficient photodetectors.•Photoconductor performance parameters evaluated for different UV light intensities.•Excellent reproducibility in performance was observed at all illuminated UV light. The improvement in UV photoconductor device performance has been significantly realized by comprising the ZnS based nano/micro-structures. In the present work, a simple one-step hydrothermal technique has been implied to synthesize the ZnS based microspheres, and it has been utilized for the UV photoconductor device applications. FESEM analysis revealed that as-synthesized ZnS possesses the shape of a microsphere with nanosheets on its surface. The size of the microspheres and the thickness of the nanosheets is found to be ~1.5 (±0.3) µm and ~22 (±3) nm, respectively. The current-voltage (I-V) and current-time (I-T) measurements have been carried out under different UV light exposures, and various photoconductor performance parameters have been investigated systematically. The sensitivity and on/off ratio are estimated to be 0.21–0.35 and 1.21–1.35, respectively. However, responsivity and detectivity are found to be 2.74 × 10−4–8.94 × 10−5 A/W and 2.02 × 109–6.51 × 108 Jones, respectively. Improved responsivity and detectivity along with the faster rise/fall time (0.153/0.206 sec) are associated to higher active surface area and porosity that provided a higher number of active sites for charge carrier generations under UV light exposure.