Silica-sol-based spin-coating barrier layer against phosphorous diffusion for crystalline silicon solar cells

Abstract

The phosphorus barrier layers at the doping procedure of silicon wafers were fabricated using a spin-coating method with a mixture of silica-sol and tetramethylammonium hydroxide, which can be formed at the rear surface prior to the front phosphorus spin-on-demand (SOD) diffusion and directly annealed simultaneously with the front phosphorus layer. The optimization of coating thickness was obtained by changing the applied spin-coating speed; from 2,000 to 8,000 rpm. The CZ-Si p-type silicon solar cells were fabricated with/without using the rear silica-sol layer after taking the sheet resistance measurements, SIMS analysis, and SEM measurements of the silica-sol material evaluations into consideration. For the fabrication of solar cells, a spin-coating phosphorus source was used to form the n+ emitter and was then diffused at 930°C for 35 min. The out-gas diffusion of phosphorus could be completely prevented by spin-coated silica-sol film placed on the rear side of the wafers coated prior to the diffusion process. A roughly 2% improvement in the conversion efficiency was observed when silica-sol was utilized during the phosphorus diffusion step. These results can suggest that the silica-sol material can be an attractive candidate for low-cost and easily applicable spin-coating barrier for any masking purpose involving phosphorus diffusion.

Functionalizable Sol-Gel Silica Coatings for Corrosion Mitigation

“…It is a method with enormous potential, applicable not only within the laboratory environment but also, importantly, on an industrial scale, where its commercial potential can be exploited to the full [ 22 ]. Numerous studies devoted to this issue report various modifications related to coating methods for obtaining functional and durable sol-gel coatings [ 2 , 3 , 25 , 37 , 38 , 39 , 56 , 67 ] synthesis procedures, including changes in the composition [ 40 , 42 ] and processing of coatings [ 37 ]. Sol-gel coatings are characterised by low thickness, which poses particular requirements to researchers investigating the morphology and properties of these coatings.…”

“…There are many techniques available that are suited for coating metallic substrates, such as physical vapour deposition (PVD), chemical vapour deposition (CVD), electrochemical deposition, dip-coating, spin-coating, painting and ultrasonic methods [ 4 , 26 , 35 , 38 , 39 , 40 , 41 ] The selection of a suitable coating technique is determined by the properties required of the coating layer. For the sol-gel method, the most frequently used coating techniques are dip-coating and spin-coating [ 26 ].…”

“…The application of spin-coating, where the coating material is dripped onto the substrate and is spread by spinning ( Figure 3 ), enables the formation of ultrathin coatings where the layer thickness is controlled by the selection of the rotational speed of the spin-coater and viscosity of the sol [ 26 , 38 , 39 ] While this method can form very homogenous layers, it is not easily scalable and is only applicable to flat surfaces with finite dimensions. Modifications of the spin-coating technique allow the formation of thin coatings of viscous solutions on hydrophobic substrates.…”

Visible-Light Active Flexible and Durable Photocatalytic Antibacterial Ethylene-co-vinyl Acetate—Ag/AgCl/α-Fe2O3 Composite Coating

“…Numerous coating techniques have been used to obtain photocatalytic coatings depending mostly on the application, substrate material, and the shape of the substrate to be coated. Spin-coating is a straightforward method that allows us to obtain reproducible and uniform coatings on relatively flat surfaces, the coating thickness and morphology can be easily adjusted by selecting the appropriate rotation speed, time, and/or depositing several layers [6][7][8].…”

Biocide mechanism of highly efficient and stable antimicrobial surfaces based on zinc oxide–reduced graphene oxide photocatalytic coatings

“…29 In the spin-coating process, the film thickness and morphology can be modulated by depositing successive layers of coating and selecting the appropriate rotation speed. 30,31 Fast operation, cost-effectiveness and good repeatability are additional advantages of this procedure. 32 The aim of this work was to combine the remarkable electrical and mechanical properties of rGO with the high antibacterial performance of ZnO nanoparticles to prepare improved photoactive bactericidal surfaces by a spin-coating technique using a sol-gel preparation method.…”