In this study, the density functional theory (DFT) is used to investigate the effect of the incorporation of Al (donor) in the Zn-site and N (acceptor) in the O-site of ZnO. The detailed theoretical study highlights the confirmation of p-type conductivity and bandgap (0.58 and 0.21 eV) narrowing exhibits in N- and (Al-N)-doped ZnO systems. p-type nature is explicitly observed by introducing acceptor bands at the top of the valance band (VB). Whereas, degenerate n-type conductivity is seen in Al-doped ZnO and a widened bandgap of 2.70 eV is attributed to Burstein-Moss (BM) effect. The calculated value of the effective mass of the (Al-N)-doped ZnO system is lower than that of the un-doped ZnO. Enhancement of the absorption and photoconductivity in the visible region for N- and (Al-N)-doped ZnO could be due to the availability of more density of states. Importantly, reflectivity, refractive index, transmittance, dielectric constants, and optical band gap have also been calculated. Higher transmittance of the samples suggested that these could be suitable for the window material of solar cells. The optical bandgap value supports the electronic bandgap value. Therefore, our finding would be helpful to design high-performance homo-junction based electronic and optoelectronic devices.

‘Goldberg criterion’ [Goldberg and Smith, Phys. Rev. Lett. 29 (1972) 500] tells that at sufficiently high energies, where pronounced refractive scattering with nuclear rainbow oscillations are followed by an ‘exponential-type falloff’ in the angular distribution, discrete ambiguities are eliminated for the deep monotonic potential. The criterion is also confirmed in the work of Bartnitzky et al. [Phys. Lett. B 365 (1996) 23] on the 16 O+ 16 O elastic scattering in the energy range of 250 - 704 MeV. However, their finding ‘using model-independent potentials’ suggests that heavy-ion elastic scattering data unambiguously favour deep potentials. The Goldberg criterion is examined in our work for non-monotonic shallow potentials using the 16 O+ 16 O elastic scattering at energy region up to 350 MeV.

The differential, integrated elastic, total, momentum transfer, viscosity cross sections and spin-polarization for electron and positron elastic scattering from carbon monoxide (CO) molecule are calculated for the energy range of 1 eV–10 keV. The work also includes the calculations of inelastic and total ionization cross sections for the same scattering system. Calculations of the above scattering observables for CO over such a wide range of energy are reported for the first time. Single scattering independent atom model (IAM) and the screening correction within the same framework, are used for the present analysis. Dirac partial wave analysis is used to calculate the phase-shifts required for the generation of the scattering observables, using a complex optical model potential. Comparison of our calculated results with the available experimental observations and other theoretical calculations is presented. The screening corrected independent atom model is found to provide better description of the results than the IAM.

ZnO is an attracted semiconducting material because of the intriguing structural, electronic and optical properties as well as the properties can easily be tuned for applications. However, p-type doping is an essential research interest to overcome the hindering of the applications of n-type ZnO for next-generation advanced electronic and optoelectronic devices. In this article, we focus on the p-type acceptor mono (Na, N) and dual (Na-N) doping effects on the structural, electronic and optical properties of ZnO using first-principles calculations based on the density functional theory (DFT). Detailed DFT analysis reveals that the structure of ZnO distorted resulting in (Na, N) and (Na-N) doping, respectively. Band structure calculation highlights the confirmation of p-type ZnO for both types of doping introduced by acceptor impurity bands at the top of the valence band and pushing the Fermi level into the valence band. The band gap of ZnO is increased for Na and Na-N doping, while decreases for N doping. The widening of the band gap with Na and Na-N doping could be explained by Burstein Moss effect. In this study the band gap can be tuned in between 0.58 and 0.93 eV. Importantly, enhancement of the absorption and photoconductivity in the near band edge region attributed to (Na, N) and (Na-N) could be extended its applications in high-performance p-type based electronic and optoelectronic devices.

The experimental differential cross-sections of O-16 + O-16 elastic scattering in the energy range 75 MeV <= E (lab) <= 1120 MeV are analysed using families of non-monotonic (NM) shallow nucleus-nucleus potential in the framework of the optical model. The experimental data is reproduced successfully using six families of NM potentials. It is found that all families converge at 350 MeV. The clear indication of the convergence of the potential families at 350 MeV conforms to the Goldberg criterion concerning the removal of discrete ambiguities even for the shallow NM potential. The study further suggests that the energy of convergence heralds the occurrence of the primary rainbow at that incident energy.

Nonmonotonic (NM) nucleus-nucleus potentials from the energy-density functional (EDF) theory including the Pauli principle have been considered for the nuclear incompressibility K in the range 188-266 MeV. The experimental cross sections of the O-16 + O-16 elastic scattering over the 31-350 MeV incident energies have been analyzed in the optical model using the NM potentials. Sensitivity of K on the elastic scattering data is studied and its value for infinite cold nuclear matter deduced to be 222 +/- 5 MeV.