Fabrication of (Au, Mn)/ZnPc/Ag Interfaces as Radiowave/Microwave Band Filters

Abstract

Herein, zinc phthalocyanine (ZnPc) layers are used as an active material to fabricated radiowave/microwave band filters. The thin layers of ZnPc are coated onto Au and Mn thin‐film substrates to form ohmic and Schottky interfaces, respectively. The Au/ZnPc and Mn/ZnPc devices are structurally and electrically characterized by means of X‐ray diffraction and impedance spectroscopy techniques in the frequency domain of 0.01–1.80 GHz, respectively. The structural investigations show that both interfaces exhibit strained structures of the monoclinic phase of ZnPc. It is also observed that while the Au/ZnPc/Ag devices display negative capacitance (NC) effects in the microwave region above 1.46 GHz, the Mn/ZnPc/Ag devices show resonance–antiresonance capacitive response in the radiowave region accompanied with NC effects in the range of 0.06–1.80 GHz. In addition, analyses of the reflection coefficient spectra have shown the ability of the (Mn, Au)/ZnPc/Ag interfaces to behave as a typical high‐/low‐bandpass filters. The filters can be operated in microwaves and radiowave ranges. The return loss spectral investigations on these filters have shown their ability to reach the market standards.

Design and Characterization of Au/CdSe/GeO2/C MOSFET Devices

“…The effect of thickness and deposition rate is also evident from the calculated free carrier density. The free carrier density for films prepared at slow rates decreased from 2.18 20 10 × cm -3 to 7.24 17 10 × cm -3 as the film thickness is increased from 250 to 500 nm. The large number of free carriers (~2 0 hand, increasing the thickness is mentioned enhancing the mobility of charge carriers in thin film transistors.…”

“…. The good consistency between the experimentally determined and theoretically estimated conductivity and capacitance spectral data assures the domination of the quantum mechanical tunneling at low frequencies below 760 MHz and the domination of correlated barrier hopping at high frequencies [15][16][17][18] . The poor fitting of the total conductivity at high frequencies (1000-1600 MHz) can ascribed to the existence of more than one kind of correlated and tunneling barriers which needs additional fitting to explore its origin 19 .…”

Design of Au/Cdbr2/Au as Negative Capacitance Devices and as Band Filters Suitable for 4G Technologies

“…The decaying conductivity provide information about the dominant current conduction mechanism in the samples. Our trails which included tests for possible domination of current conduction mechanisms arrived at the result that the most preferable conduction is by correlated barriers hopping (CBH) in which the conductivity takes the form [19][20][21] ,…”

“…These classes of devices play important roles in communication technology. The negative capacitance (NC) effects devices are used as noise reducers, parasitic capacitance cancellers and as signal amplifiers 19,20,24 . NC effect is reported resulting from the depolarization field that produces a decreasing voltage across the capacitance while the induced charge is increasing 25 .…”

“…It is also believed that the NC effect could have resulted from a minority charge injections caused by the accumulation of minority carriers at the crystallite boundaries 26 . Available models which take into account the minority carrier injection includes the Ershov-Qasrawi approach 19,20,27,28 . In this approach, the interpretation of NC is based on the analysis of the timedomain transient current in response to a small voltage step or impulse that includes a self consistent treatment of carrier transport, carrier injection and recharging.…”