Gallium nitride (GaN) is a hard material with a Wurtzite
crystal structure that has substantial impact in the electronics industry.
The XRD analysis revealed seven sharp diffraction peaks in the 29 range from 20[degrees] to 80[degrees]=31.7, 34.3, 36.24, 47.46, 56.68, 63.0 and 67.8, which were found to be consistent with the reported standard Braggs's diffraction of , , , , ,  and  planes, characteristic of typical wurtzite
type polycrystals (38).
The d values of ZnO nanoparticles calculated using the Bragg's relation, d = [lambda]/(2 sin[theta]), were 0.28, 0.26, 0.25, 0.19, 0.16, 0.14, 0.137, and 0.135 nm corresponding to (1 0 0), (0 0 2), (1 0 1), (1 0 2), (1 1 0), (1 0 3), (1 10), and (2 0 1) planes, respectively, which can be indexed to that of hexagonal wurtzite
structure of ZnO .
The grown of ZnO Wurtzite
structure occurs along the c-axis, the energy polar surfaces such as +- (0001) (Fig 6A) which exist as O2- terminated or Zn2+ is relatively high.
ZnO, an II-VI semiconductor with noncentrosymmetric wurtzite
crystal structure, a direct band gap of 3.37 eV, and a large excitation binding energy of 60 meV, has been extensively investigated because of its potential applications in piezoelectric devices , transistors , photodiodes , and photocatalysis .
According to Figure 2, the spectra are dominated by two peaks centered at ~569 [cm.sup.-1] and 736 [cm.sup.-1] and attributed to [E.sub.2] and [A.sub.1] phonon modes, respectively, for both epi-GaN and np-GaN, in agreement with the Raman selection rules for wurtzite
gallium nitride (GaN) has attractive optoelectronic applications, such as light emitting diode and laser diodes [1,3-5], this compound is used in the present work to perform numerical applications.
Qualitative phase analysis shows that a polycrystalline phase of hexagonal zinc oxide with the wurtzite
structure is formed after annealing.
Study of standard data JCPDS 76-0704 confirmed that the synthesized materials are hexagonal ZnO phase (wurtzite
ZnO is a direct wide bandgap semiconductor with a bandgap energy of about 3.37 eV at room temperature and has a large free exciton binding energy of about 60 meV [1-3].
The XRD spectrum in Figure 6 indicates a polycrystalline structure matching the hexagonal wurtzite
structure of ZnO .
Farzaneh, "Synthesis of ZnO nanocrystals with hexagonal (Wurtzite
) structure in water using microwave irradiation," Journal of Sciences, Islamic Republic of Iran, vol.