The growth and thermodynamical feasibility of tungsten diselenide single crystals using chemical vapour transport technique

Abstract

Therrnodynamical feasibility study and the growth of layer structured transition metal dichalcogenide single crystals of WSc 2, using iodine as transporting agent, has been reported in this paper. The characterization of the grown samples have been done by X-ray analysis. Keywords. Transition metal dichalcogenide; tungsten disclenide; chemical vapour transport; thermodynamical feasibility.

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

“…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 thickness of the metal film was 1000 Å and the pressure inside the chamber was ≈ 10 -6 Torr.…”

“…[1][2][3][4] The high optical absorption, layered arrangement between the cations, high resistance against photo-corrosion, inherently stable nature against the electrolytic environment and the optically matching magnitude of bandgap makes WSe 2 a prominent material in photoelectrochemical conversion and photovoltaic solar energy conversion [5][6][7]. WSe 2 in their thin film forms are well known for their self lubricating properties.…”

Preparation and Crystal Growth of Transition Metal Dichalcogenides

“…[125] The sublimation of WS 2 (direct vapor transport (DVT)) was also described. [169] WSe 2 : (a) [72,83,97,116,128,129,166,168,[170][171][172][173][174][175][176][177][178] , (b) [134] On (a): Chemical vapor transport is also the preferred crystallization method for WSe 2 . Iodine is used particularly frequently as a transport additive.…”

“…Iodine is used particularly frequently as a transport additive. [28,72,166,168,175,177,178] Bromine is also suitable. [129] According to the literature, the addition of bromine should lead to WSe 2 crystals of better quality.…”

Thermodynamic feasibility study for chemical vapour deposition of some ternary crystals using iodine and hydrogen iodide

“…Venkatesan et al [12] proposed a thermodynamical analysis of chemical vapour transport of ternary chalcogenides taking the elements as source materials. Prediction of minimum source temperature (Ts), minimum growth temperature (Td), the influence of temperature and transporting agent concentration on growth were successfully done [13] on the basis of this model. In the present work an attempt has been made to assign the source and growth temperatures of some selected ternary chalcogenides using iodine and hydrogen iodide as transporting agents.…”