Far Infrared Optical Properties of Bulk Wurtzite Zinc Oxide Semiconductor

Ooi, P. K.; Lee, Saicheong; Ng, Shashiong; Hassan, Z.; Hassan, H. Abu

doi:10.1016/s1005-0302(11)60092-3

Cited by 11 publications

(4 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Till date, there are certain reports on optical properties of bulk and nanostructured ZnO in infrared region and the eld is still wide open as per its potential in device application. [40][41][42][43][44][45][46][47] For example, García-Serrano et al 41 used far infrared (FIR) reectance spectra for the qualitative determination of free carrier density in metal and semiconductor nanoclusters embedded ZnO lms. On the other hand, Yamamoto et al 42 focused on the optical surface phonon modes in small ZnO crystals using FIR transmission measurements at room temperature.…”

Section: Resultsmentioning

confidence: 99%

Far-infrared optical constants of ZnO and ZnO/Ag nanostructures

et al. 2014

View full text Add to dashboard Cite

We report on the synthesis of ZnO nanoplates and ZnO nanoplate/Ag nanoparticle heterostructures via a simple and cost effective wet chemical precipitation method. The prepared samples were characterized for structural and optical properties by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), UV-VIS reflectance, Raman, and FT-IR spectroscopy. The Kramers Kronig (K K) method and classical dispersion theory was applied to calculate the far-infrared optical constants such as, refractive index n(u), dielectric constant 3(u), transverse optical phonon (TO) and longitudinal (LO) optical phonon modes. We determined various optical constant values n(u) and 3(u) for ZnO nanostructures in the range of 0 to 9 and 0 to 70, respectively. Whereas, for Ag deposition on ZnO nanostructures, the corresponding n(u) and 3(u) values were found to be increased in the range of 0 to 30 and 0 to 800, respectively. The TO and LO optical phonon modes of ZnO nanoplate/Ag nanoparticle heterostructures were also found to be higher (416 cm 1 , 620 cm

show abstract

Section: Resultsmentioning

confidence: 99%

Far-infrared optical constants of ZnO and ZnO/Ag nanostructures

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Dielectric constant shown in Fig. 4 44 and phonon 43 contribution to ε 2 has been taken from literature 43,44 . An additional contribution to ε 2 due to BMP at 120 GHz has been assumed in such a way that ε 1 agrees with modelled ε r .…”

Section: Discussionmentioning

confidence: 99%

Increased static dielectric constant in ZnMnO and ZnCoO thin films with bound magnetic polarons

Vegesna

Bhat

Bürger

et al. 2020

Sci Rep

View full text Add to dashboard Cite

A novel small signal equivalent circuit model is proposed in the inversion regime of metal/(ZnO, ZnMnO, and ZnCoO) semiconductor/Si 3 N 4 insulator/p-Si semiconductor (MSIS) structures to describe the distinctive nonlinear frequency dependent capacitance (C-F) and conductance (G-F) behaviour in the frequency range from 50 Hz to 1 MHz. We modelled the fully depleted ZnO thin films to extract the static dielectric constant (ε r) of ZnO, ZnMnO, and ZnCoO. The extracted enhancement of static dielectric constant in magnetic n-type conducting ZnCoO (ε r ≥ 13.0) and ZnMnO (ε r ≥ 25.8) in comparison to unmagnetic ZnO (ε r = 8.3-9.3) is related to the electrical polarizability of donor-type bound magnetic polarons (BMP) in the several hundred GHz range (120 GHz for CdMnTe). The formation of donor-BMP is enabled in n-type conducting, magnetic ZnO by the s-d exchange interaction between the electron spin of positively charged oxygen vacancies V o + in the BMP center and the electron spins of substitutional Mn 2+ and co 2+ ions in ZnMnO and ZnCoO, respectively. The BMP radius scales with the Bohr radius which is proportional to the static dielectric constant. Here we show how BMP overlap can be realized in magnetic n-ZnO by increasing its static dielectric constant and guide researchers in the field of transparent spintronics towards ferromagnetism in magnetic, n-ZnO.

show abstract

“…In Fig. 3, the heat flux carried by various relevant closerange mechanisms are compared, including the near-field radiative heat transfer (NFRHT, [5,7]) for ZnO [30,31] and Au [32], phonon tunneling for Au mediated by van der Waals force [19] and electrostatic force (for 1 V bias across the vacuum) [20,21], and the blackbody radiation (maximal far-field radiative heat transfer). In panel (a) of Fig.…”

mentioning

confidence: 99%

“…3 (a) is that the NFRHT of ZnO is particularly strong. This happens [7] because the surface-phonon polaritons of ZnO can be excited at infrared frequencies [30,31], matching the spectrum of the room temperature thermal photons, and hence enhancing the heat flux. But this also infers that one should expect a strong attenuation of the NFRHT once the excitations are stopped, i.e.…”

mentioning

confidence: 99%