| Summary: | 碩士 === 國立中央大學 === 材料科學與工程研究所 === 102 === In this thesis, dilute spin-on solutions of boric acid and phosphoric acid in de-ionized (DI) water, low-cost and non-toxic alternative to more conventional boron diffusion sources like boron tribromide (BBr3) which are toxic and pyrophoric. It was found that boron emitters with a wide range sheet resistances (~4 – 20 Ω/sq.) could be achieved with very dilute boric acid sources (~0.5-6 wt.% boric acid in DI water) by controlling the diffusion time and temperature.
We have studied the application of annealing processing for boron and phosphorus diffusion using spin-on dopants (SODs). For the diffusion, an extended gettering process, both P and B diffusion at 850oC、900oC、950oC、1000oC、1050oC followed by in-situ gettering at different temperature for one hour, gave better lifetime values than the standard gettering for all compensation levels. The lifetime of highly compensated materials were increased significantly by such an extended gettering process. Cell efficiency up to 11.9 % has been achieved on 1x1cm2 cells with the boron emitter and the phosphorus BSF formed with boric acid and phosphoric acid, respectively.
Finally, we fabricate monocrystalline N-type silicon solar cell get the optimized result, and there we have the electro-optic convert efficiency = 13.13%, the open-circuit voltage (Voc) = 580.40 mV, short-circuit current density (Jsc) = 34.07 mA/cm2, and the fill factor (FF) = 65%.
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