Fabrication Of Ordered Nano-array Structures Based On Anodic Alumina Templates And The Application To SERS

In1959, Feynman predicted materials would show different characteristics fromtheir macro state when the sizes are small enough. More and more scientists paidattention to the concept of nanotechnology since then. With the decades’ developmentof nanotechnology, nano-materials have shown superior performance in every area. Inthe21stcentury, world powers have turned to how to industrialize nano-materials. If wecould fabricate nano-array structure, then the collective effect of nano-materials will befully exerted. At present, there are a lot reports about nano-array structures used inenergy, chemical sensing and semiconductor industry. In our work, the porous anodicalumina film (AAO) was introduced to fabricate nano-rod and nano-dot array structure,meanwhile the Ag nano-dot array was introduced to Raman detection.The way to fabricate nano-array structure using AAO templates is not only easybut also able to get nano-rod, nanotube and nano-dot with different sizes, because of theuniform, ordered and controllable AAO structure. However, generally, the preparednano-materials will collapse to each other once the template was removed. In our work,we electrodeposited CdSe nano-rod arrays free standing on ITO substrates modifiedusing poly vinyl alcohol (PVA) with many hydroxyl groups. After the modification, theadhesion between an ultrathin AAO template and an ITO substrate will be greatlyimproved. CdSe nano-rod array would not collapse when the AAO template wasremoved after the modification. In addition, highly ordered Ag nano-dot arrays wereobtained by using an AAO template for thermal evaporation followed by removing ofthe ultrathin AAO template.Noble metal nanoparticles have surface enhancement Raman scattering (SERS)effect. The orderd Ag nanodot array was used to detect the dye R6G Raman signal. Itwas found that the signal showed high uniformity and reproducibility with a relativestandard deviation (RSD) about13%due to the highly ordered structure of Ag nano-dotarray. When it was introduced to DNA detection, the singnal could be detected when the concentration of DNA was as low as10-11M.Finally, random Ag nanoparticle array was fabricated using an annealing method.And then a second layer of Ag was deposited on the top of random Ag array. It wasfound that the SERS singnal of R6G would be enhanced by7times compared with thatof the random Ag nanoparticle array without the second Ag layer. It was simulatedusing FDTD (Full name is needed). And it was found that the similar effect could beobtained when depositing other metals such as gold on the random Ag nanoparticlearray.Solar cells and supercapacitors made of nano-array structures are also preliminarilystudied.