Atmospheric pressure chemical vapour deposition of selenium and tellurium films by UV laser photolysis of diethyl selenium and diethyl tellurium

Abstract

Excimer laser-induced photolysis of gaseous diethyl selenium and diethyl tellurium (C 2 H 5 ) 2 M (M = Se, Te) is controlled by cleavage of both M-C bonds, it yields C 1 -C 4 hydrocarbons (ethene as major product) and results in chemical vapour deposition of selenium films and nanosized tellurium powder. The selenium and tellurium properties were characterized by X-ray photoelectron spectroscopy and Scanning electron Microscopy techniques.

Room-Temperature Reaction between Laser Chemical Vapor Deposited Selenium and Some Metals

“…and is accompanied by minor radical routes giving rise to propane, propene, methane, and ethyne. 29 All the hydrocarbons are inert and do not interfere with the deposition of elemental selenium. The selenium coatings deposited on quartz, glass, and KBr stay whitish for an extended period of time.…”

“…The ArF laser irradiation of the gaseous diethyl selenium in nitrogen atmosphere results in efficient cleavage of both C−Se bonds, formation of C 1 −C 4 hydrocarbons, and instant formation of a white selenium fog that slowly descends onto the reactor glass walls where it creates initially white and later pinkish coatings of amorphous selenium . This photolysis affording ethene as a major product takes place mostly as β-elimination of ethene (a major path: (C 2 H 5 ) 2 Se → Se + 2C 2 H 4 + H 2 ) and is accompanied by minor radical routes giving rise to propane, propene, methane, and ethyne .…”

“…We have previously reported on UV laser-induced gasphase photolysis of several organoselenium compounds for chemical vapor deposition of selenium films. [29][30][31][32][33] Dialkyl selenides 29,30,32 and selenophene 31,33 irradiated by ArF or KrF lasers were efficiently photolyzed into selenium, which produced thin Se layers upon deposition to Al and glass. Here we report that the UV laser photolysis of gaseous diethyl selenium and consecutive Se deposition onto several metals results in some cases (Ag, Cu, Cd, Mg, Zn) in the formation of metal selenide.…”

Laser Photolysis and Thermolysis of Organic Selenides and Tellurides for Chemical Gas-phase Deposition of Nanostructured Materials

“…However, these radical species can be rejected on the basis of analysis of hydrocarbon products. Thus the KrF and ArF laser photolysis of diethyl telluride and diethyl selenide in excess of He [ 48 , 49 ] proceeds as a one-photon process with initial quantum yield 0.08-0.10 (Se) and 0.4-0.5 (Te) and yields ethene (a far major product), n-butane, ethane, propane and propene (minor products). These data were accounted for by the pulse laser energy sufficient to break both C-X (X=Se, Te) bonds and by an unimportant role of cleavage of the C 2 H 5 radical (and its subsequent combination and disproportionation reactions).…”

A solvothermal route to tellurium based thin films

“…One-dimensional (1D) nanostructured tellurium thin films are of particular interest because the optical and electrical properties of devices strongly depend on the thin film microstructures, due to their quantum confinement effect. In the past several decades, various techniques, including: the epitaxial growth of thin single crystalline tellurium films on NaCl (001) [5], decomposition of H 2 Te on PE foils [6], low energy cluster beam deposition (LECBD) [7], tellurium films by UV laser photolysis of tellurophene or dimethyl tellurium [8,9], electrochemical synthsis [10], laser-induced chemical vapour co-deposition process [11], laser gas-phase pyrolysis of dimethyl tellurium [12] and cathodic electrodeposition [13], have been exploited to prepare tellurium thin films. Compared to other methods, CBD method is simpler, without complicated operation, without high temperature, without costly equipments.…”