DISPERSION IN IMPEDANCE SPECTRA OF ISOTYPE CdO–ZnO THIN FILM HETEROSTRUCTURE ON APPLIED DC BIAS

Abstract

Radio frequency magnetron sputtering technique has been used to prepare n–n isotype heterostructure of CdO–ZnO thin film on glass substrate. The energy band structure analysis shows the formation of charge accumulation and charge depletion region created near the interface of CdO–ZnO n–n isotype heterostrucure which leads to the formation of a junction capacitance. The impedance spectroscopic studies of CdO–ZnO isotype heterostructure show an excellent dispersion in the impedance spectra as observed in the Nyquist plot depending on applied DC bias voltage. The frequency response of impedances has been explained from band structure and equivalent electrical circuit model of the heterostructure. These studies will be highly significant in exploring the possibility of application of such isotype interfaces in optimizing the functionality of organic and inorganic electronic devices and solar cells.