Microwave Impedance Spectroscopy and Temperature Effects on the Electrical Properties of Au/BN/C Interfaces

Abstract

In the current study, an Au/BN/C microwave back-to-back Schottky device is designed and characterized. The device morphology and roughness were evaluated by means of scanning electron and atomic force microscopy. As verified by the Richardson–Schottky current conduction transport mechanism which is well fitted to the experimental data, the temperature dependence of the current-voltage characteristics of the devices is dominated by the electric field assisted thermionic emission of charge carriers over a barrier height of ~0.87 eV and depletion region width of ~1.1 μm. Both the depletion width and barrier height followed an increasing trend with increasing temperature. On the other hand, the alternating current conductivity analysis which was carried out in the frequency range of 100–1400 MHz revealed the domination of the phonon assisted quantum mechanical tunneling (hopping) of charge carriers through correlated barriers (CBH). In addition, the impedance and power spectral studies carried out in the gigahertz-frequency domain revealed a resonance-antiresonance feature at frequency of ~1.6 GHz. The microwave power spectra of this device revealed an ideal band stop filter of notch frequency of ~1.6 GHz. The ac signal analysis of this device displays promising characteristics for using this device as wave traps.

Highly efficient hydrogen sensors based on Pd nanoparticles supported on boron nitride coated ZnO nanowires

“…First of all, it is reasonable to consider the roles of BN and Pd on the sensing behavior of ZnO NWs. In BN coated ZnO as shown in Figure 8a, since a thin (5±2 nm) BN film is coated around the ZnO NWs, due to the work function difference between ZnO and BN, 84,85 in intimate contact between ZnO and BN electrons from ZnO are transferred to BN and Schottcky barriers (height of 5.52 eV) will be formed on the interfaces between ZnO and BN (Figure S12a), which can expand the electron depletion layer relative to pristine ZnO NWs. Upon…”