Schottky diode characteristics: Aluminium with 500 and 1000 Å thicknesses on p type WSe₂ crystal

Abstract

The conduction properties of Al-pWSe 2 Schottky barrier diodes prepared identically but with different metal thickness are reported here. The p type WSe 2 semiconducting crystals used in the present study was grown by direct vapour transport technique. The current-voltage characteristics of these diodes were analyzed from 140 K to 300 K on the basis of thermionic emission theory applying Gaussian distribution. Below 200 K, deviations were observed in barrier height, ideality factor and Richardson plot. Hence at lower temperatures, a model has been considered where the total current is assumed to be the sum of thermionic emission, generation recombination and tunneling components. The observed deviations in the diode parameters were successfully interpreted in terms of the contribution of these multiple charge transport mechanisms across the interface of the fabricated diodes. The diode with a thickness of 500 Å Al showed more homogeneous nature than with 1000 Å.

Photoelectric Characteristics of Isotype Heterostructure p-WSe2/p-Si Photodetector with Improved Photoresponsivity and Detectivity

“…Detectivity is an essential parameter that represents the ability of a detector to detect low optical signals and can be assessed by D * = R A 1 / 2 / false( 2 italiceI dark false) 1 / 2 where A is the area of the device where effective absorption of incident light occurs (∼2165.13 μm 2 ), R is the responsivity, e is the electronic charge, and I dark is the dark current, which is 10 nA at a bias of −3 V. The corresponding changes in detectivity and photoresponsivity with the illumination power are shown in Figure c. A decrease in both detectivity, and responsivity was observed with an increase in light intensity, which can be attributed to enhanced exciton combination at high carrier concentrations . This phenomenon can be attributed to the interface between Si and WSe 2 and trap states having defects and charged impurities in the WSe 2 monolayer.…”

“…A decrease in both detectivity, and responsivity was observed with an increase in light intensity, which can be attributed to enhanced exciton combination at high carrier concentrations. 28 This phenomenon can be attributed to the interface between Si and WSe 2 and trap states having defects and charged impurities in the WSe 2 monolayer. Previously, antisite defects and selenium vacancies were reported by Ding et al, 29 and the CVD-grown WSe 2 monolayer was the most defective (for example, the density of selenium vacancies reached 1.48% in atomic ratio).…”

Schottky Barriers on Layered Anisotropic Semiconductor – WSe<sub>2</sub> – with 1000 Å Indium Metal Thickness

“…One side of the crystal was cleaved with adhesive tape to get a more homogeneous surface with large terraces of non-reactive van der Waal's plane for metal deposition. The surface preparation techniques were described in detail elsewere [18]. 2 High purity indium metal (Aldrich 99.99%) was thermally evaporated at the rate of 0.2 Å/s onto the cleaved front surface of the crystal through a shadow mask to form circular Schottky contacts of area of 3.6 × 10 -3 cm 2 .…”

“…The focus was mostly on understanding the contact properties as well as conduction properties. We have already reported the mechanisms of charge transport in In-pWSe 2 with 500 Å metal thickness [18]. Here we have carried out a systematic investigation on the temperature dependence of the electrical properties of these structures with 1000 Å metal thickness over a wide temperature range and its comparison with 500 Å metal thickness In-pWSe 2 diode.…”

Electrical and optical characteristics of Au/PbS/n-6H–SiC structures prepared by electrodeposition of PbS thin film on n-type 6H–SiC substrate

“…Schottky barrier height (SBH) in metal/semiconductor (MS) is a fundamental parameter for the rectifying contacts [4][5][6][7][8][9][10]. The presence of another semiconductor thin film with nanometer thickness at the MS interface in the Schottky contacts introduces a new method in the control of fundamental device parameters [10][11][12][13][14][15].…”