Ryoki Nomura

Single-source organometallic chemical vapour deposition process for sulphide thin films: Introduction of a new organometallic precursor BunIn(SPri)2 and preparation of In2S3 thin films

Abstract Single-source organometallic chemical vapour deposition was successfully introduced using Bu n In(SPr i ) 2 as a precursor molecule and tetragonal β-In 2 S 3 thin layers with a strongly preferred (103) growth orientation were obtained on Si(111) and quartz substrates at a substrate temperature T sub of 300–400°C. A dependence of growth rate that lay between 25 and 450 nm h −1 on source temperature T source (60–80 °C) and on T sub was observed. β-In 2 S 3 thin films thus obtained were photoresponsive, with optical band gap energies and dark conductivity estimated as 1.98 eV and 2.0 × 10 −4 S cm −1 respectively. Furthermore, a polycrystalline In 6 S 7 layer, which is one of the sulphur-deficient phases of indium sulphide, was grown when T sub was raised to 450°C in the same single-source system.

Oxygen- or sulphur-containing organoindium compounds for precursors of indium oxide and sulphide thin films

Abstract Dibutylindium carboxylates and butylindium thiolates are prominent precursors for the preparation of indium oxide and sulphide thin layers via a solution pyrolysis process. Their application has been enlarged to include the preparation of ternary compound thin films, taking advantage of the formation of binuclear complexes with organotin oxides or copper(II) dithiocarbamate complexes. Thus, addition of Bu2nIn(OCOEt) to Bu2n SnO gave the mixed stannoxane Bun(EtCOO)In SnBu3n (I). While, Bun2InSPrn and Cu(S2CNBu2n)2 afforded similar bimetallic complexes Bu2iIn(SPrn)Cu(S2CNBu2n) (VI). Solution pyrolysis of I and VI gave uniform indium-tin oxide and copper-indium sulphide thin films, respectively. The course of thermal decomposition of I and VI was also investigated.

Facile synthesis of antimony dithiocarbamate complexes

Antimony(III) oxide could react readily with dithiocarbamic acids (R1R2NCS2-H, where R1, R2 = C1-C8 alkyls, alkylenes and C2H4OC2H4) and gave the corresponding antimony(III) dithiocarbamates in good yields (45–94%) at 15°C. Novel β-hydroxy or β-cyanoethyl dithiocarbamates were prepared via the condensation in 88–98% yields (R1, R2 = CH2CH2OH, R1 = Me, and R2 = CH2CH2OH; R1 = Bun, and R2 = CH2CH2CN). The larger anisobidenticity among the antimony dithiocarbamate complexes was introduced in the Sb-S2CN moieties by hydrogen bonding from β-hydroxyl groups which was confirmed by IR, and 1H and 13C NMR spectroscopy. The quinquevalent inorganic Sb2O5 and Sb2S5, and organometallic PhSbO3H2 and Ph3SbO, gave tervalent products. In the reactions with diethylamine and CS2 the former three compounds afforded the corresponding dithiocarbamates and the last gave triphenylstibine, but Ph4SbOH gave the quinquevalent Ph4SbS2CNEt2.

Sulfur‐Doped Indium Oxide Thin Films as a New Transparent and Conductive Layer Prepared by OMCVD Process Using Butylindium Thiolate

Thus we attempted to prepare In 2 O 3 films via vapor phase decomposition of Bu 2 InSPr i and it was found that the thiolate gave highly conductive and transparent In 2 O 3 films under slightly oxygenated carrier gas systems

Thermal decomposition of organoindium compounds and preparation of indium-tin-oxide films

Abstract Organoindium compounds of general formula Bu 2 InX [where X is OBu t , OPh, O 2 CEt, O 2 CPh, O 2 CCH(Et)(CH 2 ) 3 CH 3 or C 5 H 7 O 2 (acetylacetonate)] were synthesized, and their thermal decomposition was investigated by means of thermogravimetry. The main pyrolysis of the dibutylindium compounds was exothermic and their thermal weight loss occurred below ca 400°C. In contrast, metallo-organics such as In(acac) 3 and In[O 2 CCH(Et)(CH 2 ) 3 CH 3 ] 3 decomposed endothermically in the temperature range between 190 and 480°C. Chemical liquid pyrolysis of dibutylindium octanoate and propionate in p -xylene below 450°C, along with dibutyltin oxide as a dopant, gave highly conductive ( ca 10 −3 Ω cm) and transparent indium-tin-oxide films.

Preparation and characterization of n- and i-butylindium thiolate

Abstract Butylindium thiolates BuxnIn(SR)3-x (x = O, R = Prn, Ph; x = 1, R = Pri, Hexc, Ph; x = 2, R = Prn, Pri, Hexc, Ph) and BuxiIn(SR)3-x (x = 1, R = Ph; x = 2, R = Prn, Pri, Ph) are prepared in the reaction of Bu3In and corresponding thiols in ether. Monothiolates can be obtained from all Bu3In-alkanethiol combinations, but di- and trithiolates are isolated only from less hindered ones such as Bu3nIn-PrnSH. While, more acidic benzenethiols can give mono-, di- and trithiolates. The mono- and dialkylthiolates, are distillable liquids and they are characterized by means of NMR spectroscopy (1H and 13C). In contrast, the phenylthiolates are solids and have poor solubility in organic solvents. The molecular weight measurements show that the dithiolates are generally monomeric in solution.

Preparation of novel metal dithiocarbamate complexes containing ω-OH group. Stabilization effect of the OH group on the HNCS2-Mt linkage

Abstract The direct condensation between metal oxide powders (Zn II , In III , Sb III and Bi III ) and dithiocarbamic acids, prepared by the reaction of ethanolamine or 1,3-propanolamine with CS 2 , gave corresponding metal dithiocarbamate complexes in good yields. Although antimony and bismuth dithiocarbamates decomposed up to 80°C to give elimination products such as oxazolidine-2-thione, thiazolidine-2-thione or bis(3-hydroxypropyl)thiourea, the zinc and indium derivatives were recovered after heating in benzene at 80°C for 6 h. In the reactions of organometallic oxides such as Bu 2 SnO, BuSnO 2 H and Ph 3 SbO with the dithiocarbamic acids, the elimination products were directly obtained even at 20°C.

Synthesis and characterization of novel macrocyclic antimony car☐ylates containing disulfide bonds

Abstract Novel 18- and 22-membered ring cyclic antimony car☐ylates which contained two S S bonds were synthesized in the one-pot oxidative-coupling/condensation reaction of triphenylstibine oxide with thioglycolic or β-thiopropionic acids, respectively.