Modulation of optoelectronic properties of ZnO/PbO core/shell nanocomposite for memcapacitive application

ZnO/PbO core/shell nanocomposites embedded in PVP matrix has been carried out by adopting chemical route with increase in volumetric core/shell ratio. The XRD study shows the hexagonal structure of ZnO and orthorhombic structure of PbO nanocomposites as prime phases. The average grain size and strain are found to increase after coating. Details of structural morphology were analyzed using FESEM and HRTEM techniques. The particle size calculated from HRTEM is found out to be 2.97 and 3.54 nm for ZnO core and ZnO/PbO core/shell nanocomposite respectively which is consistent with those UV–Vis measurements. Absorption studies exhibit the blue shift of the prepared ZnO samples from their bulk counterpart. The absorption edge of the prepared ZnO/PbO core/shells is systematically red shifted from that of core ZnO as the volume of the shell increases whereas the PL intensity reduces after shelling.This effect may be attributed to a systematic decrease of respective band shift at the interface after increase of thickness of shell. Thus, the electrical properties of prepared core/shell nanocomposites act as prominent type II core/shell that can be used as conductive devices. Here the characteristics of mem capacitive devices using ZnO/PbO core/shells have been presented that exhibit promising properties of pinch-off voltage and current with shelling. The I–V measurements show the conduction mechanism is ohmic at low bias and as Richardson-Schottky type in the high bias region. All those structural and optoelectronic optical properties are co-related with the shell thickness for better application in mem-devices.