Effect of Boron doping on the structural, optical and electrical properties of ZNO nanoparticles produced by the Hydrothermal method

Effect of boron doping with 0-11 at. {\%} concentration on structural, optical and electrical properties of Zinc oxide nanopowder synthesized by Hydrothermal method has been reported. XRD results reveal that all B doped ZnO nanopowders have single phase hexagonal structure without any impurity. Positions of main diffracted peaks of ZnO shifted slightly towards small 2$\theta $ angle and grain size decreases from 60.39 nm to 34.34 nm with an increase of B doping. SEM analyses indicate that the doping concentration of B affected the surface morphology of ZnO nanostructures. Optical properties were examined by UV--Vis absorption/diffuse reflectance spectroscopy. The optical band gap of Zn$_{\mathrm{1-x}}$B$_{\mathrm{x}}$O nanostructures increased from 3.27 to 3.30 eV with increasing doping from x$=$0 to x$=$0.11. The role of B doping on the transport properties was searched by temperature dependent Hall measurements in range of 180--350 K. The carrier concentration of the samples increased from 0.11x10$^{14}$ to 4.08x10$^{14}$ cm$^{\mathrm{-3}}$, the Hall mobility decreased from 5.61 to 1.22cm$^{2}$V$^{-1}$s$^{-1}$ and electrical resistivity decreased from 10.89 $\times$ 10$^{4}$ to 1.25 $\times$ 10$^{4}$ ohm-cm with the increase of B doping at room temperature. The electrical resistivity was observed to decrease with both the increase in dopant concentration and the temperature.