Size- and morphology-dependent optical properties of ZnS:Al one-dimensional structures

Abstract

Typical morphology substrates can improve the efficiency of surface-enhanced Raman scattering; the need for SERS substrates of controlled morphology requires an extensive study. In this paper, one-dimensional ZnS:Al nanostructures with the width of approximately 300 nm and the length of tens um, and micro-scale structures with the width of several um and the length of tens um were synthesized via thermal evaporation on Au-coated silicon substrates and were used to study their size effects on Raman scattering and photoluminescent spectra. The photoluminescence spectra reveal the strongest green emission at a 5 at% Al source, which originates from the Al-dopant emission. The Raman spectra reveal that the size and morphology of the ZnS:Al nanowires greatly influences the Raman scattering, whereas the Al-dopant concentration has a lesser effect on the Raman scattering. The observed Raman scattering intensity of the saw-like ZnS:Al nanowires with the width of tens nm was eight times larger than that of the bulk sample. The enhanced Raman scattering can be regarded as multiple scattering and weak exciton—phonon coupling. The branched one-dimensional nanostructure can be used as an ideal substrate to enhance Raman scattering.

White light tunable emissions from ZnS: Eu3+nanophosphors over 330–465 nm excitation range for white LED applications

“…Also, Eu 3+ is the most stable isotope of europium at higher temperatures (Sharma et al 2006) and so was not expected to be reduced to the Eu 2+ in a sulfurizing atmosphere. Moreover, as earlier noted, point defects and surface states are found to be the major contributors to the broad band emission in ZnS (Fang et al 2011, Reddy et al 2014, Zeng et al 2015.…”

“…Also, the deconvoluted bands obtained when the S4 sample was excited by a blue light emitting source at 465 nm wavelength are centered at: Sagayaraj 2012). The green luminescence in the range 481 to 516 nm can be attributed to electron transfer involving sulfur vacancies (Wang et al 2011, Zeng et al 2015. The possible reduction of Eu 3+ to Eu 2+ was not observed in both the excitation and emission spectra.…”

Effect of Ag on structural, optical and luminescence properties of ZnS nanoparticles synthesized by microwave-assisted chemical route

“…We observed symmetric broad band near 160, 258 and 350 cm -1 for undoped ZnS nanoparticles. The broad peak near 258 cm -1 is assigned to LO mode while 350 cm -1 is assigned to the TO mode of cubic ZnS nanoparticles [23]. The LO and TO modes for bulk cubic ZnS are reported previously at 276 and 352 cm -1 [24].…”

Polarization Simultons in Stimulated Raman Scattering by Polaritons

“…We introduce the principal axes of the tensor To verify (31), we were using the parameters of crystals widely used in optical display and storage, optical communication network, optical detection, etc. such as ZnO [29]- [35] and ZnS [36] [37] [38] [39]. Figure 2 shows the intensity as a function of the polariton frequency in zinc blende ZnS in the range 200 -400 cm −1 .…”