Barrier type silicon-based thin film semi-laminated solar cell

Abstract

The invention relates to a silicon-based thin film semi-laminated solar cell, in particular to a barrier type silicon-based thin film semi-laminated solar cell with different doping densities and forbidden band widths on various layers. The barrier type silicon-base thin film semi-laminated solar cell structurally comprises P2I2P1I1N1 and P1I1N1I2N2. The barrier type silicon-based thin film semi-laminated solar cell not only combines the advantages of a laminated cell and a gradually changing band gap thin film cell, but also increases the total thickness of an I layer of a solar cell relative to a PIN structure, thereby providing more places for electron-hole pair generation; the generated photon-generated carriers have enough kinetic energy to move to both anode and cathode of the solarcell by enhancing the effects of P2 and P2 and strengthening a barrier electric field positioned in I, and therefore the short-circuit current and the open-circuit voltage of the solar cell are increased; meanwhile, filling factors and conversion efficiency are greatly enhanced; in addition, matching of an intermediate layer and a buffer layer is not needed, and the excessive interfacial effect of the laminated cell can be reduced.

Description

technical field [0001] The invention relates to a silicon-based thin-film solar cell, in particular to a barrier-type silicon-based thin-film semi-stacked solar cell with different doping concentrations and forbidden band widths of each layer. Background technique [0002] At present, silicon-based solar cells are mainly monocrystalline silicon, polycrystalline silicon, and thin-film silicon solar cells. Thin-film solar cells are mainly single-junction PIN structures and stacked solar cell structures. Among them, single-junction amorphous silicon cells with PIN structures Although it can absorb more solar spectrum, due to the instability of amorphous silicon, the battery has S-W effect, which limits the stability of its performance, and stacked solar cells have been greatly developed. Hydrogenated amorphous silicon cells As the top cell, the microcrystalline silicon amorphous silicon stacked cell with hydrogenated microcrystalline silicon cell as the bottom cell is a hot spo...

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Problems solved by technology

[0002] At present, silicon-based solar cells are mainly monocrystalline silicon, polycrystalline silicon, and thin-film silicon solar cells. Thin-film solar cells are mainly single-junction PIN structures and stacked solar cell structures. Among them, single-junction amorphous silicon cells with PIN structures Although it can absorb more solar spectrum, due to the instability of amorphous silicon, the battery has S-W effect, which limits the stability of its performance, and stacked solar cells have been greatly developed. Hydrogenated amorphous silicon cells As the top cell, the microcrystalline silicon amorphous silicon stacked cell with hydrogenated microcrystalline silicon cell as the bottom cell is a hot spot in current research and application. Although stacked solar cells can make full use of the solar spectrum, it is necessary to increase the thickness of the absorbing layer. At the same time, an intermediate reflective layer or buffer layer is introduced to increase the absorption of light by the intrinsic layer of amorphous silicon, thereby increasing the current, and finally improving the overall performance of the laminated battery. Different combinations of laminated batteries make the selection of the intermediate layer very difficult. At the same time, the production process has become more complicated. With the in-depth study of the optical properties of silicon thin films, it has been found that the band gap can be gradually changed by strictly controlling the grain size and crystal composition of the I layer, thereby increasing the absorption of the spectrum.

[0003] Cai Ning, Geng Xinhua et al. Research progress on the interlayer of amorphous / microcrystalline silicon stacked cells [J]. Acta Solaris Sinica, 2009.30(3):338-339 discloses an amorphous / microcrystalline silicon stacked cell for For different amorphous microcrystalline silicon solar cells, in order to achieve their current matching, it is necessary to introduce a technical solution to improve their performance by introducing an intermediate layer, but the intermediate layer must meet various technical requirements, such as being limited by the thickness of the top cell and low cell thickness. And the limitation of the refractive index, with the existing technology, the selection of the intermediate layer is a difficult problem, and it brings more interface effects to the laminated battery

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