Q2. Why was the ITO substrate chosen for this study?
The ITO substrate wast adopted for this study due to it is transparency in the visible region and low price compared to the Si and GaN substrates, respectively.
Q3. What is the effect of the Sm doping on the nanorods?
The growth rate of the nanorods was suppressed by the Sm doping ZnO nanorods as seen by FE-SEM where the density and length of the nanorods decreased upon Sm doping concentration.
Q4. What is the optical band gap of wurtzite ZnO?
Since the band gap of wurtzite ZnO is a direct band gap, the optical band gap can be calculated using Tauc’s law [45]: (αhν)2 = C(hν − Eg) (4) where, α is the absorption coefficient, hν is the phonon energy, C is constant and Eg is the optical energy gap.
Q5. What is the purpose of this study?
The purpose of this study is to investigate the effect of Sm doping on the crystallization, photoluminescence, Raman scattering, UV-vis, and electrical properties at room temperature.
Q6. What is the FWHM of the 440 cm1 peaks?
The peak at 440 cm−1 appears to be sharp and narrow and dominates in the Raman scattering spectra, a good indication that as-synthesised samples have high crystallinity, and is supported by the XRD results.
Q7. What is the PL emission in the green-yellow part of the visible light spectrum?
The broad emission (deep-level emission) in the green-yellow part of the visible light spectrum is due to different point defects, either intrinsic [52, 53, 54] or extrinsic [55].
Q8. What was the XPS data obtained at room temperature?
X-ray photoelectron spectroscopy (XPS) data were acquired at room temperature with a SPECS Phoibos 150 electron energy analyser, using a monochromatized Al Kα photon source (hν = 1486.71 eV).
Q9. What is the B0 value of the ZnO nanorods?
The obtained ΦB0 values from the fit for undoped and Sm doped ZnO nanorods at 1.5 at.% were found to be 0.55 eV and 0.72 eV, respectively.
Q10. How many minutes were used to make sure the solution is homogeneous?
It should be mentioned that the zinc and the dopant sources were dissolved separately, stirred for 10 minutes and finally mixed together and stirred again for another 15 minutes to make sure the homogeneous solution are obtained.
Q11. What is the peak of the UV emission of pure ZnO?
This peak may be attributed to the transition in energy in ZnO between anelectron in Zn interstitial defect states and a hole in the valence band.
Q12. What is the effect of the Sm doping on the ZnO nanorods?
the FWHM increased with increasing Sm doping concentrations indicating that more defects were introduced into the ZnO nanorods.
Q13. What are the main techniques used to synthesize ZnO nanoparticles?
Various techniques have been used to synthesize ZnO nanoparticles, for example chemical vapor deposition [24], pulse laser deposition [25], molecular beam epitaxy [26], sol-gel [27] and chemical bath deposition (CBD) [28, 29, 30].
Q14. How many molars of zinc acetate were used to clean the substrates?
It should be mentioned that the molar ratio of zinc acetate to MEA was kept 1:1. ITO substrates were cleaned with ethanol, deionized water, acetone and deionized water ultrasonically 5 minutes each, in this sequence and finally nitrogen gas was used to blown the substrates dry.
Q15. What is the FWHM of the peaks at 440 cm1?
As one can see in the inset of Fig. 3, the peaks at 440 cm−1 are slightly shifted towards lower wavenumber when increasing the Sm doping concentration.
Q16. What is the UV emission of pure ZnO?
It should be noted that the UV emission shows a small peak around 388 nm and it becomes more pronounce with increasing the Sm content (see Fig. 5).
Q17. What is the effect of UV emission on ZnO nanorods?
The presence of strong UV emission of pure and Sm doped ZnO nanorods in PL spectra indicate that the as-synthesized samples have a good crystal quality with excellent optical properties compared to work reported by Jingyuan et al. [18] and Velusamy and co-workers [50].