| Summary: | 碩士 === 國立臺北科技大學 === 光電工程系研究所 === 103 === In this paper, the photovoltaic performance of silicon solar cells using the surface plasmon resonance effects（SPR）generated through the different metal nanoparticles are investigated. The uniform size and high order metal nanoparticles were obtained by using Anodic Aluminum Oxide (AAO) as masks. With the same of pore size and thickness of AAO template, the same size and shape metallic nanoparticles can be deposited on the silicon cells. The metalic nanoparticles exhibited SPR localized electric field to enhance light absorption in the solar cells as well as to enhance the photocurrent (Iph) and conversion efficiency (η).
Fabrication of AAO templates including: (1) The 4N (99.997%) aluminum foil was placed in acetone and washed for 5 minutes with ultrasonic shock. (2) The aluminum foil was annealed at 400℃ for 3 hours and electrochemical polished. (3) AAO film was grown on the Al foil surface during an anodizing process. (4) The pore size was widened in a solution of 10% phosphoric acid. (5) A transparent poly-[methyl methacrylate](PMMA, C5O2H8) was coated on top side of AAO. (6) Remove the aluminum substrate. (7) Remove oxide barrier layer to obtain AAO template.
Then we deposited a titanium dioxide (TiO2) passivation layer on the silicon solar cell. AAO template was then transferred on to the silicon solar cell. The 30 nm thick metallic(Ag、In、Al) films were deposited on three silicon solar cells respectively, through the AAO mask by E-beam, and then all samples treated with a thermal annealing process. The thickness and the size of nanopore of AAO template are examined using scanning electron microscope (SEM). Finally, reflectivity, external quantum efficiency (EQE), dark I-V and photovoltaic I-V characteristics of the silicon solar cell are measured and compared. Under AM 1.5G of illumination at 25oC, the obtained characteristics of the solar cell are shown as the following: (1) After deposition of Ag nanoparticles (Ag NPs), the SPR contribute to short-current density enhancement (ΔJsc) is 10.58% and the conversion efficiency enhancement (Δƞ) is 11.31%；(2) After deposition of In nanoparticles (In NPs), short-current density enhancement (ΔJsc) is 7.81% and the conversion efficiency enhancement (Δƞ) is 9.05；(3) After deposition of Al nanoparticles (Al NPs), short-current density enhancement (ΔJsc) is 3.27% and the conversion efficiency enhancement (Δƞ) is 7.58%. Thus, Ag nanoparticles plasmonic silicon solar cell exhibited the best improving in EQE and conversion efficiency in this study.
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