In this paper, simple relations are proposed for the calculation of Debye temperature θ D and melting point T m of II-VI and III-V zincblende semiconductors. Six relations are proposed to calculate the value of θ D . Out of these six relations, two are based on plasmon energy data and the others on molecular weight, melting point, ionicity and energy gap. Three simple relations are proposed to calculate the value of T m . They are based on plasmon energy, molecular weight and ionicity of the semiconductors. The average percentage deviation of all nine equations was calculated. In all cases, except one, it was estimated between 3.34 to 17.42 % for θ D and between 2.37 to 10.45 % for T m . However, in earlier correlations, it was reported between 10.59 to 33.38% for θ D and 6.96 to 14.95% for T m . The lower percentage deviation shows a significant improvement over the empirical relations proposed by earlier workers. The calculated values of θ D and T m from all equations are in good agreement with the available experimental values and the values reported by different workers.

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Graphene nanoribbons (GNRs) are expected to display extraordinary properties in the form of nanostructures. The effect of boron and nitrogen substitutional doping at four successive positions on electronic and transport properties of zigzag graphene nanoribbons (ZGNRs) is studied using spin-unpolarized density functional theory. It has been observed that the electronic structures of the doped ZGNRs are different from those of pristine ZGNRs. We have also calculated the transformation energy in the form of total energy. The substitutional boron atom at the nanoribbons edges suppresses the energy band near Fermi level by changing properties of material from metallic to semi-metallic in ZGNRs which can be explained as a consequence of the edge polarization effects. At all doping positions, N-doped ZGNRs are n-type while B-doped ZGNRs are p-type semiconductors. These substitutionally B-and N-doped impurities act as scattering centers for transport in GNRs. Due to unusual properties of these nanomaterials, they can be used in carbon-based nanoelectronics devices.

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