Journal of Electronic Materials | 2019
Experimental Study of Different Vanadium Dopant Concentrations in ZnO Nanorods for a Low Frequency Piezoelectric Accelerometer
Abstract
Nano-electro-mechanical systems accelerometers using undoped (Z) and 1\xa0wt.%, 3\xa0wt.% and 5\xa0wt.% of Vanadium doped (ZV1, ZV3 and ZV5) Zinc Oxide (active layer) nanorods are fabricated. A low temperature assisted hydrothermal method was used to grow nanorods on Fluorine-doped Tin Oxide substrates. The complete accelerometer device architecture includes formation of a p-n junction by depositing poly (3,4-ethylene dioxythiophene)\xa0polystyrene sulfonate (p-type layer) on V doped and undoped active layers (n-type layer) with silver as top electrode. The structural analysis revealed the (002) plane c-axis orientation of 1 D nanorods grown. A field emission scanning electron microscope with energy dispersive x-ray spectroscopy showed changes in the morphology in the undoped and doped devices. Optical analysis showed a band gap decrease from 3.15\xa0eV (Z) to 2.92\xa0eV (ZV5). Photoconductivity study proved the formation of a p-n junction between the p-type and active layer in all the fabricated piezoelectric accelerometers. The Nyquist plots obtained using impedance analysis depicted the presence of RC circuit in all the fabricated accelerometers. A less internal resistance of 1.26\xa0kΩ and RC time constant of 0.032\xa0ms for ZV5 showed an improved piezoelectric property due to 5\xa0wt.% of V doping compared to other fabricated accelerometers. The highest sensitivity of 3.528\xa0V/g was acquired for ZV5 with maximum output voltages of 2.30\xa0V and 2.9\xa0V at 9\xa0Hz resonant frequency and 1\xa0g acceleration, respectively. An improvement of 77.28% sensitivity in ZV5 was observed compared to that of Z.