Summary: | 碩士 === 國立清華大學 === 工程與系統科學系 === 98 === This paper is studying the fabrication and characterization of heterojunction solar cell, we deposited intrinsic amorphous silicon on single crystal silicon substrate and P-type and N-type layer was formed by ion implantation methods, can be formed emitter and the back surface field quickly. Amorphous silicon single-crystal silicon solar cells can improve the response in the short wavelength (<600nm) of light and amorphous passivate surface of single crystal silicon layer can enhance short circuit current (Jsc) of the solar cell significantly.
Implantation of boron ions also implanted fluoride at the same time by BF2 ion source, density of state can be reduced by fluoride ion in amorphous silicon ,and the solar cell anneal in the hydrogen environment after metal electrodes deposition, silicon binding with hydrogen can reduce dangling bonds in silicon surface substantially as well as annealing in the hydrogen environment can make the contact well on metal and silicon surface. We also introduced the manufacturing process of SiC, band gap of SiC is more than 2eV, SiC could make the emitter and the silicon substrate with greater potential energy, the greater of the electric field to accelerate the of electron and hole by light illuminate and separate them quickly. The amorphous silicon as the emitter with a problem of poor conductivity to transverse carrier transport, which we add a layer above the emitter indium tin oxide (ITO) to improvement. 800 A of ITO also has anti-reflective effect near the wavelength of 600nm, so ITO can enhance the short-circuit current(Jsc) of solar cells.
We can learn a lot of ways to enhance the efficiency of solar energy from studying the heterojunction solar cells. Enhance the conversion efficiency of solar cells could greatly reduce the cell cost, if we manufacture solar cell with thinner silicon substrate, simpler and low temperature process ,and to produce more high-efficiency solar cells, solar cell will be able to reduce our
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