花状铜锌锡硫纳米颗粒的溶剂热法制备和结构表征

以金属氯化物为金属源,硫脲为硫源,聚乙二醇和乙二醇为混合溶剂,采用溶剂热法一步合成了花状的铜锌锡硫纳米颗粒.利用X射线衍射仪,扫描电子显微镜、能谱仪、透射电子显微镜、紫外-可见分光光度计分析了铜锌锡硫纳米颗粒的物相、结构、形貌及光学性能,并初步探讨了铜锌锡硫的生长机理.结果表明,所得到的铜锌锡硫纳米颗粒具有锌黄锡矿结构,直径在500～2 000nm范围内可调,其中花状的铜锌锡硫纳米颗粒由大量厚度约25nm的纳米片构成.所制备的铜锌锡硫纳米颗粒对可见光具有明显的吸收;利用外延法推算得到其禁带宽度约为1.5eV,与太阳能电池所需的最佳禁带宽度相近,显示其有望在新一代太阳能电池中得到应用和推广.

Synthesis of flower-like Cu2ZnSnS4 nanoparticles by solvothermal method and characterization of their structure

Flower-like Cu2ZnSnS4(CZTS) nanoparticles were successfully synthesized via simple solvothermal method by using metal chloride and thiourea as the precursors in the presence of polyethylene glycol and ethylene glycol as the mixed solvent.The phase,structure,morphology and optical properties of as-obtained CZTS nanoparticles were characterized by powder X-ray diffraction,scan electron microscopy,energy dispersive spectrometry,transmission electron microscopy and ultraviolet-visible spectrophotometry,and the growth mechanism of CZTS was primarily explored.Results show that as-obtained CZTS nanoparticles are pure kesterite-type CZTS with diameter adjustable in a range of 500-2 000 nm,while the flower-like CZTS nanoparticles consist of nanosheets with a thickness of about 25 nm.Besides,as-obtained Cu2ZnSnS4 nanoparticles show a broad absorption band in the visible region;and their band gap,estimated from long wavelength extrapolation of the band edge,is 1.5 eV.Such a band gap is close to the optimum band gap for solar cells,indicating that as-obtained CZTS may have potential application in solar cells.