Microstructural, chemical states and electrical properties of Au/CuO/n-InP heterojunction with a cupric oxide interlayer

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>Cupric oxide (CuO) is synthesized by simple chemical bath deposition method and deposited on n-type InP substrate using e-beam evaporation technique. First, the structural and chemical compositional analysis of CuO/n-InP are analysed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). XRD and XPS results confirmed that the formation of CuO on n-type InP substrate. Then, Au/CuO/n-InP heterojunction is fabricated with a CuO interlayer and correlated its results with the Au/n-InP Schottky junction (SJ). The barrier height (Φ<SUB>b</SUB>) and ideality factor (n) are extracted through I-V and C-V methods and the respective values are 0.66 eV (I-V)/0.80 eV (C-V) and 1.24, and 0.78 eV (I-V)/0.94 eV (C-V) and 1.62 for the SJ and HJ diodes, respectively. By applying Cheung's and Norde functions, the Φ<SUB>b</SUB>, ideality factor and series resistance (R<SUB>S</SUB>) are derived for the SJ and HJ diodes. The derived interface state density (N<SUB>SS</SUB>) of HJ is lower than the SJ; results demonstrated that the CuO interlayer plays an important role in the decreased N<SUB>SS</SUB>. The Poole-Frenkel emission is the dominant current conduction mechanism in reverse bias of both SJ and HJ diodes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Structural and chemical properties of CuO films are analysed by XRD and XPS. </LI> <LI> Barrier height of Au/n-InP SJ was modified by CuO interlayer. </LI> <LI> Heterojunction has a good rectification ratio compared to the Schottky junction. </LI> <LI> The interface state density of HJ is lower as compared to the SJ. </LI> <LI> Poole-Frenkel mechanism is found to dominate in both SJ and HJs. </LI> </UL> </P>