Researchers in Prof. Yi Cui\'s laboratory have developed a versatile low-cost solution-based deposition process for producing high quality thin film layers for solar cells and other electronic devices. This technology called air-stable ink rolling (AIR) uses ink made from low-cost commercially available precursors with relatively low toxicity to produce dense contaminant-free large grain layers. AIR can be used to produce absorber layers for photovoltaics [Cu2ZnSn(SeS)2) CIG(Se S)]; buffer layers for photovoltaics (ZnS ZnO In2S3); or for transparent conducting oxides in thin film transistors (ITO AZO ZnO). Stage of Research: The inventors have used this process to produce large-grain CuInS2 CZT(SSe) ZnO In2O3 AZO and ITO. They have also demonstrated the ability to use the CuInS2 material to make solar cells. Ongoing Research: The inventors are focused on improving the photovoltaic conversion efficiency of devices made from the AIR process. They are also developing the process for additional materials and using the materials to produce thin film transistors.
1) Low-cost commercially available precursors 2) High quality: process is able to make both large grain sulfides and selenides layers are uniform dense and contaminant free 3) Versatile: range of materials that can be produced includes Cu2ZnSn(SeS2) CIG(Se S) ZnS ZnO In2S3 ITO and AZO any metal can be added to the ink so new compounds and dopants can be investigated 4) Air-stable - unlike many nanoparticle syntheses which are air-sensitive 5) No additional processing of ink - no extra synthesis to make precursors (unlike nanoparticles) and no additional additives to form good coatings 6) Safe materials - the chemicals used are not highly toxic or explosive