Laminated photovoltaic device and production method thereof

Abstract

The invention provides a laminated photovoltaic device and a production method thereof, and relates to the technical field of photovoltaics. The laminated photovoltaic device comprises an upper-layer battery unit, a lower-layer battery unit, and a tunnel junction located between the upper-layer battery unit and the lower-layer battery unit; the lower-layer battery unit is a crystalline silicon battery; the tunnel junction comprises an upper crystalline silicon layer, a lower crystalline silicon layer, and an intermediate layer located between the upper crystalline silicon layer and the lower crystalline silicon layer; the upper crystalline silicon layer, the lower crystalline silicon layer and the intermediate layer are in direct contact, and the doping types of the upper crystalline silicon layer and the lower crystalline silicon layer are opposite; the doping concentration of the upper crystalline silicon layer at the interface with the intermediate layer and the doping concentration of the lower crystalline silicon layer at the interface with the intermediate layer are both greater than or equal to 10<18> cm<-3>; the intermediate layer comprises at least one dielectric layer; and the band gap width of the dielectric layer is greater than or equal to 3 eV. According to the invention, the efficiency of the laminated photovoltaic device is improved, the series resistance is reduced, and the peak tunnel current is improved.

Description

technical field [0001] The invention relates to the field of photovoltaic technology, in particular to a laminated photovoltaic device and a production method. Background technique [0002] Stacked photovoltaic devices can divide sunlight into multiple bands. From the front to the back, solar cells with gradually decreasing band gaps are used to absorb sunlight of different energies in order to broaden the spectral response band to sunlight and reduce energy loss. Therefore, stacked photovoltaic devices have broad application prospects. Stacked photovoltaic devices with crystalline silicon cells as the underlying cell unit have a large space for mass production. [0003] Tunnel junctions have strong transmission and recombination capabilities, and the thickness required to achieve high recombination rates is relatively thin. Therefore, tunnel junctions are usually used to connect battery cells in series in stacked photovoltaic devices. [0004] However, in the prior art, t...

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Problems solved by technology

[0005] The invention provides a laminated photovoltaic device and a production method, aiming to solve the problems of low tunnel junction tunneling efficiency and high overall series resistance of the laminated photovoltaic device in which the lower battery unit is a crystalline silicon cell

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