英语翻译The preparation of ultrafine powder of bismuth sulfideTh
英语翻译
The preparation of ultrafine powder of bismuth sulfide
The synthesis of binary metal sulfides has been the focus of attention because of their important physical and chemical properties [1,2],good commercial applications in semiconductors,pigments,luminescence devices,solar cells,IR detectors and optical fiber,communications,modern thermoelectric coolers [3].Bismuth sulfide (Bi2S3) is a direct band gap material with Eg of 1.3 eV [4] and useful for photodiode arrays of photovoltaics [5].Usually,busmuth sulfide can be prepared by direct reaction of bismuth and sulfur vapor in a quartz vessel at high temperature [6].The chemical deposition method was applied to prepare bismuth sulfide through reaction of bismuth salt complexed by triethanolamine or EDTA with an aqueous solution containing a sulfur sourse such as thioacetamide,thiourea,sodium thiosulphate,geseous H2S.However,the powders obtained through this route are mostly amorphous or poorly crystallized [7–10].The thermal decomposition preparation of bismuth sulfide was also reported by thermal decomposition of bismuth dithiocarbamate complexes [11],metal ethylxanthate [12],Bi-thiourea complex [13].However,all these methods required high temperature or else the final poducts contain some impurites.Some researches use nonagueous solutions for depostion of bismuth sulfide thin films,but they have got amorphous products [14,15].Yu and Qian reported thermal synthesis of Bi2S3 through a reaction of BiCl3 and thiourea in ethanol
at 140 °C [16].