A Study Of Nano-ink-coating Technology In Preparation Of CIGS-based Thin Film Solar Cells Absorbing Layer

Energy crisis is the common problem faced by countries around the world. Withthe reserves reducing of conventional energy and the problem of environmentalpollution, the industrialization of thin film solar cell is very important today. TheNano-ink-coating technology has the advantage of low cost, simple process, shortpreparation time, and easy to large area production. But the ink mixing process istedious, at the same time, the dispersity of ink and smoothness of film are poor, thatlimits the development of nano-ink-coating technology in industrialization of CIGS.In this thesis, the ink mixing process and the film coating process is optimized,improving the dispersity of ink and smoothness of film. At the same time, weinvestigate the cost reduction of CIGS thin film solar cells with elements replacing,making it more suitable for industrialization. The main conclusion and contents of thisthesis were stated as follow.(1) Mixing ink with different method. By SEM observation we found thatreducing the degree of centrifugation and washing, the dispersity of ink andsmoothness of film is improved.(2) CIGS thin films was prepared by selenium annealing with doubletemperature zone tube furnace. The morphology of CIGS thin films prepared bycoating-drying cycle technology is porosity by SEM observation. With the time ofselenium annealing extend from40min to60min, the crystallinity of thin film getbetter.(3) CIGS thin films was prepared by screen printing. The more compactmorphology of film with the method of coating-thermolysis cycle technology wasobtained compared with coating-drying cycle technology by SEM observation.Withing the coating-thermolysis cycle technology, the organics in the film which wasdeposited by the ink with oleylamine wrapped CIGS nanocrystals can be volatilizedand decomposed more completely compared to the coating-drying cycle technologyby XRD diffraction pattern analysis.(4) The CZTSe precursor ink is prepared by ball-milling and CZTSe thin film isprepared by spin-coating method. With the water bath ultrasonic testing, we foundthat film-forming property is improved by adding appropriate amount ofethyecellulose. With XRD diffraction pattern analysis, Carbon and oxygen impurityare brought to the film by adding ethyecellulose, reducing the crystallinity of film. With the time of selenium annealing extend from10min to30min, thedecomposition of ethyecellulose get more complete, improving the crystallinity offilm.