A simple method of manufacturing oxide-based nano-structured materials using a chemical wet process has been developed by Korean scientists Sang-Hyeob Kim (Daejeon-city, KR), Hye-Jin Myoung (Daejeon-city, KR), Sung-Lyul Maeng (Chungcheongbuk-do, KR), Sunyoung Lee (Seoul, KR) and G.A.J Amaratunga (Cambridge, GB).
The process can be employed to manufacture oxide-based nano-structured materials with uniform composition and good electrical characteristics in large quantities. The oxide-based nano-structured materials, such as zinc oxide nanowires, can be used in various fields such as bio sensors/ chemical sensor devices, solar cells, light emitting diodes (LEDs), or display devices.
The process and materials are described in U.S. Patent Application 20100055016. The method is a chemical wet process in which an organic solution that includes a transition metal or a semi-metal element is mixed with another organic solution and oxide-based nano-structured materials are grown through a chemical reaction accompanied by the mixing of the two solutions; and a physical dry process in which the grown oxide-based nano-structured materials are controlled to have a uniform composition and to have stable structure.
Fabrication is a relatively simple process which does not use large growing equipment. The method includes preparing a first organic solution that comprises a metal, mixing the first organic solution with a second organic solution that contains hydroxyl radicals (--OH), filtering the mixed solution using a filter in order to extract oxide-based nano-structured materials formed in the mixed solution, drying the extracted oxide-based nano-structured materials to remove any remaining organic solution, and heat treating the dried oxide-based nano-structured materials.
Oxide-based nano-structured materials that include transition metals and semi-metal elements have potential applications in a wide range of fields, for example, nano-electronic devices (such as field effect transistors (FETs), single electron transistors (SETs), photodiodes, and biochemical sensors), solar cells, or display fields, and are the subject of research efforts worldwide.
The method can be employed to manufacture large quantities of oxide-based nano-structured materials with uniform composition, a uniform shape, and a uniform size. The oxide-based nano-structured materials have stable optical and electrical characteristics. Also a substrate is not used for growing the nano-structures. Thus, problems caused due to crystallographical incoherence between a substrate and the nano-structures can be avoided.
The invention was supported by the Information Technology (IT) Research & Development program of the Ministry of Information and Communication (MIC) [project No. 2005-S-605-02, project title: IT-BT-NT Convergent Core Technology for advanced Optoelectronic Devices and Smart Bio/Chemical Sensors.