Annealing temperature effects on the size and band gap of ZnS quantum dots fabricated by co-precipitation technique without capping agent

Abduelwhab B Alwany; G M Youssef; O M Samir; Mohammed A Algradee; Nabil A A Yahya; Mohamed A Swillam; Syahrul Humaidi; R Abd-Shukor

doi:10.1038/s41598-023-37563-6

Annealing temperature effects on the size and band gap of ZnS quantum dots fabricated by co-precipitation technique without capping agent

Sci Rep. 2023 Jun 26;13(1):10314. doi: 10.1038/s41598-023-37563-6.

Authors

Abduelwhab B Alwany^{1

2}, G M Youssef², O M Samir^{1

3}, Mohammed A Algradee¹, Nabil A A Yahya^{4

5}, Mohamed A Swillam⁵, Syahrul Humaidi⁶, R Abd-Shukor⁷

Affiliations

¹ Physics Department, Faculty of Science, Ibb University, Ibb, Yemen.
² Laboratory of Materials Sciences and Solar Cells, Physics Department, Faculty of Science, Ain Shams University, Abbasia, Cairo, Egypt.
³ Engineering College, Aljanad University for Science and Technology, Taiz, Yemen.
⁴ Physics Department, Thamar University, Thamar, Yemen.
⁵ Department of Physics, School of Sciences and Engineering, American University in Cairo, New Cairo, 11835, Cairo, Egypt.
⁶ Post Graduate Program (Physics), FMIPA, Universitas Sumatera Utara, Jln Bioteknologi No.1, Medan, 20155, Indonesia.
⁷ Department of Applied Physics, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia. ras@ukm.edu.my.

Abstract

ZnS quantum dots (QDs) were fabricated using the co-precipitation technique with no capping agent. The effects of different annealing temperatures (non-annealed, 240 °C and 340 °C for 2 h) on the structural and optical characteristics of ZnS QDs are reported. The samples were examined by XRD, TEM, PL, FTIR, and UV-Vis. An increase in annealing temperature led to an increase in the dot size and a lowering of the energy band gap (E_G). The average crystallite size, D of ZnS was between 4.4 and 5.6 nm. The ZnS QDs showed a band gap of 3.75, 3.74 and 3.72 eV for non-annealed, 240 °C, and 340 °C annealed samples. The reflection spectra increased in the visible light and decreased in UV region with an increase in annealing temperature. This work showed that the band gap and size of ZnS QDs could be tuned by varying the annealing temperature.

Abstract

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