tailieunhanh - Photoluminescence Emission of Cu Doped ZnS Microstructures Synthesized by Thermal Evaporation
By doping of Cu2+ ion, the absorption wavelength is shifted towards the lower wavelength being an evidence for an increasing band gap. The emission spectrum of pure ZnS has a green emission band centred at around 520 nm. By doping Cu2+ ion, the peak of the green band in the luminescence spectra were transferred to 516 nm and appeared a strong blue peak at 440 nm. The reasons of these will be discussed in this paper. | VNU Journal of Science: Mathematics – Physics, Vol. 34, No. 2 (2018) 1-7 Photoluminescence Emission of Cu Doped ZnS Microstructures Synthesized by Thermal Evaporation Nguyen Van Nghia1,2,*, Nguyen Duy Hung1 1 Advanced Institute of Science and Technology (AIST), Hanoi University of Science and Technology, (HUST), 01 Dai Co Viet, Hanoi, Vietnam 2 Thuy Loi University, 175 Tay Son, Dong Da, Hanoi, Vietnam Received 10 August 2017 Revised 05 September 2017; Accepted 15 November 2017 Abstract: Cu doped ZnS microstructures were prepared by the thermal evaporation method using ZnS powder and powder as precusor materials. The microstructures was characterized by using X-ray diffraction (XRD) analysis. The XRD studies indicated that there are two phases (ZnS and ZnO) at the undoped sample, but most of the samples are only having wurtzite (hexagonal) phase of ZnS after doping. The photoluminescence emission and photoluminescence excitation of ZnS and Cu2+ doped ZnS microstructures have been studied. The photoluminescence excitation spectra of ZnS microstructures is presented around 374 nm. By doping of Cu2+ ion, the absorption wavelength is shifted towards the lower wavelength being an evidence for an increasing band gap. The emission spectrum of pure ZnS has a green emission band centred at around 520 nm. By doping Cu2+ ion, the peak of the green band in the luminescence spectra were transferred to 516 nm and appeared a strong blue peak at 440 nm. The reasons of these will be discussed in this paper. Keywords: ZnS:Cu2+ microstructures, photoluminescence, thermal evaporation. 1. Introduction Owning the largest band gap among II – VI semiconductor, zinc sulfide (ZnS), a direct transition semiconductor, is a famous material with diverse luminescence properties [1,2], Especially in doping the transition metals or rare earth elements [3–7]. Curently, it is used in many fields such as liquid crystal displays, light emitting diodes (LEDs), cathode ray tube (CRT) .
đang nạp các trang xem trước
