Preparation of Ultrathin Functional Organic Filsm using Liquid Jet Technique

九州大学N.Nishi教授的团队研制了一种基于液体喷射技术的功能有机材料超薄膜制备装置，该装置将细束溶液注入真空中。有机物质作为溶剂溶解在溶液中。该技术具有适用于各种有机大分子的优点，装置由低真空、中真空、高真空三个真空室组成。在低真空室，液体射流通过流动泵从细小的不锈钢针中喷射出来，用于液相色谱。当光束喷射到真空中时，它会分裂成许多小颗粒，然后由撇油器选择光束的中间部分。在中真空室中，细小颗粒在内压的作用下进一步破碎，形成许多团簇。团簇光束再次通过撇油器，选定的部分被允许在高真空室中飞行，到达衬底形成薄膜。该装置是在Nishi教授的指导下设计的，由名古屋大学建造。以罗丹明B为样品材料，进行了真空试验，并采集了一些初步数据。考察了喷嘴温度、溶液流速、溶剂(水和乙醇)对测定结果的影响。用偏光显微镜、可见吸收光谱和荧光光谱对所制备的薄膜进行了表征。根据条件的不同，可以形成各种含有细小颗粒到小晶体的薄膜。下一步应该是使用菁染料形成J-聚集体。

An apparatus for fabricating ultrathin films of functional organic materials was designed and constructed based on the liquid jet technique, where a fine beam solution is injected into vacuum, developed by the group of Professor N.Nishi of Kyushu University. The organic material is dissolved in the solution as the solvent. This technique has an advantage of applicability to various large organic molecules.The apparatus consists of three vacuum chambers, low vacuum, medium vacuum, and high vacuum chmbers. At the low vacuum chamber, liquid jet is ejected through a fine stainless steel needle by a flow pump for liquid chromatography. The beam is split into many small particles when it is sprayd into vacuum, and the middle part of the beam is selected by a skimmer. In the medium vacuum chamber, the fine partcles are further broken by the internal pressure, forming many clusters. The cluster beam is again passed through a skimmer, and the selected part is allowed to fly in the high vaccum chamber to arrive at the substrate to form the thin film.The apparatus is designed following the guidance of Prof. Nishi, and constructed at Nagoya University. The vacuum test was completed, and some preliminary data was taken using rhodamin B as the sample material. The effect of the temperature of the ejection nozzle, flow rate of the solution, and the solvent (water and ethanol) were examined. The prepared films were examined by polarized microscope, visible absorption spectra, and fluorescence spectra. Depending on the conditions, various films containing fine particles to small crystals were formed. The next step should be the formation of J-aggregates using cyanine dyes.