Structural, optical, and ferroelectric behavior of Zn1−xLixO (0 ⩽ x ⩽ 0.09) nanostructures

The present study reports structural, optical and ferroelectric behavior of lithium doped zinc oxide (Zn1−xLixO with x = 0.0, 0.05, 0.07 and 0.09) nanostructures synthesized by hydrothermal method. The XRD pattern indicates the pure phase formation of ZnO without any impurity and the particle size, calculated through XRD data, is found to decreases from 51 to 42 nm for samples with x = 0-0.09, respectively. FESEM images show that the size of Li doped ZnO nanostructures decreases with increasing lithium concentrations. Moreover, Raman and Photoluminescence spectra also confirm the wurtzite phase formation of ZnO. PL spectra show a blue shift in both UV and visible region as a result of doping. A significant enhancement in optical band are found to be 3.39-4.23 eV by Li doping due to increasing carrier concentration that blocks the lowest states in the conduction band and results the increase in band gap. Further, Li incorporation enhances the room temperature ferroelectric behavior and the maximum value of polarization (Pmax) increases from 8.973 to 19.394 μC/cm2 for x = 0-0.09, respectively.