Yb/InSe/Sb2Te3/Au BROKEN GAP HETEROJUNCTION DEVICES DESIGNED AS CURRENT RECTIFIERS, TUNABLE MOS CAPACITORS AND GIGAHERTZ MICROWAVE CAVITIES

Abstract

Herein, we report the design and experimental characterization of a broken gap heterojunction devices fabricated by vacuum evaporation of Yb/InSe/Sb2Te3/Au stacked layers. The structural characterizations of the stacked layers revealed an amorphous/polycrystalline heterojunction type. The measurements of capacitance-voltage characteristics in the frequency domain of 1.0-9.0 MHz displayed tunable metal-oxidesemiconductor (MOS) characteristics. The frequency dependent built-in voltage, depletion width, and free carrier density is also investigated. In addition, the analyses of currentvoltage characteristics have shown that the device displays highly stable current rectification ratios of ~103 above 0.20 V. Moreover, the ac signal analyses in the frequency domain of 10-1800 MHz have shown the possible tunability of the conductance and capacitance over a wide range of frequency. Furthermore, the microwave cutoff frequency spectra indicated increasing cutoff frequency limits with increasing incident signal frequency. The microwave cutoff frequency reached 7.1 GHz for a propagating signal of frequency of 1800 MHz.