AACVD of Molybdenum Sulfide and Oxide Thin Films From Molybdenum(V)‐based Single‐source Precursors^**

Abstract

(S 2 COEt) 4 (2) single-source precursors (SSPs) via aerosol-assisted (AA À ) CVD onto glass substrates is reported. The films grown from 2 are achieved at a lower temperature than 1 (300 and 425°C, respectively), potentially attributable to the Chugaev elimination mechanism. Raman spectroscopy (RS) and scanning electron microscopy (SEM) show the composition of the films to be variable; films that are grown from the AACVD reaction of 1 are found to be of pure MoS 2 nanoplates, whereas those grown from 2 consist of MoO 3 microparticles and MoO 2 noncrystalline films, together with various nanostructures of MoS 2 , depending on deposition temperature. The decomposition processes of the SSPs are assessed to determine why these variations in thin films are seen.

Chemical vapour deposition of chromium-doped tungsten disulphide thin films on glass and steel substrates from molecular precursors

“…The theoretically calculated weight loss for the formation of pure WS 2 is 57.0%. Marks et al have proposed that the small difference between calculated and theoretical weight loss is due to residue in the TGA analysis of transition metal dithiocarbamate complexes.The stepwise decomposition of dithiocarbamate complexes have been previously observed, with EtSH, EtNCS, CS 2 , and H 2 S expected as the volatile by-products [40][41][42][43]. TGA of WS 3 L 2 shows rapid, initial decomposition which possibly forms WS 2 (S 2 CNEt 2 ) and the remaining dithiocarbamate slow down the further growth of WS 2 by terminating the reactive edge sites of WS 2 where growth occurs most rapidly.…”

Solution based CVD of main group materials

“…10 For example, cadmium chalcogenides have applications in solid-state solar cells, in lightemitting diodes for flat-panel displays, sensors and in field-effect transistors. For example, mixed alkyl/dithio-or diseleno-carbamates and xanthanates [12][13][14][15][16] are potential precursors to II-VI materials as they provide access to lower deposition temperatures and zinc selenide, cadmium sulfide and cadmium selenide thin films have been deposited from compounds, of the type [RM(E 2 CNEt 2 )] 2 (M = Zn, Cd, E = S, Se, R = Me, CH 2 CMe 3 ) 17 via MOCVD. 2 Low temperature growth is important because these II-VI materials interdiffuse and form defects at temperatures above 500 1C.…”

A facile method for the production of SnS thin films from melt reactions

“…The decomposition of metallo-organic xanthates is known to take place via the relatively lowtemperature and clean Chugaev elimination reaction [19]. The use of the xanthate ligand in SSPs has permitted the formation of many metal sulfides, including, but not limited to, MoS 2 [20], CdS [21], NiS, PdS [22], and CZTS [23], at lower temperatures than those needed by their respective (N,N-dialklydithiocarbamato-) analogs. Recently, we have reported the preparations of PbS/polymer composites from both lead(II)xanthate and lead(II)dithiocarbamate complexes by a melt process [18,24], finding that the decomposition of Pb(S 2 CO n Bu) 2 in a polymer matrix produced pure cubic PbS nanocrystals at 150°C; significantly lower temperatures than 275°C are needed to decompose Pb(S 2 CN n Bu 2 ) 2 .…”