TCO thin film and preparation method thereof

Abstract

The invention discloses a TCO (transparent conducting oxide) thin film and a preparation method thereof. The TCO thin film comprises three zinc oxide thin film layers containing dopants from top to bottom, wherein the atom ratios of dopants in the zinc oxide thin film layer are different in zinc oxide. In the preparation method, dopant gas flows are adjusted in the thin film growing process to form a multiple-layer structure and modulate a surface microstructure and the optical performance of the TCO thin film, wherein the middle and an interface of the multiple-layer structure are different in dosage concentration. The light trapping effect of the film and the optical transmittance of a near-infrared light region can be greatly improved while good electrical conductivity of the TCO film and the interface of the film are maintained, a haze average value of a 400-1100nm waveband is improved from 27.3% to 34.9 %, the transmittance of a 700-2000nm near-infrared waveband is improved from 76% to 77.7%, and the photoelectric conversion efficiency of batteries is improved.

Description

technical field [0001] The invention belongs to thin film preparation technology, in particular to a transparent conductive oxide thin film (TCO thin film) of a thin film solar cell and a preparation method thereof. Background technique [0002] The TCO film with texture is widely used in the thin-film solar cell industry as the front and back electrodes. It can form light traps in the cell while conducting current, thereby prolonging the propagation path of photons in the absorbing layer to increase photon utilization. rate, improve battery efficiency. [0003] At present, there are two main process routes used in the production of large-area TCO thin films. One is to use chemical vapor deposition to grow a film with a V-shaped suede structure, and the other is to use post-processing methods (such as dry method) or wet etching) to achieve the desired textured structure for films that do not have a textured structure or have a small textured structure. In the former proces...

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Problems solved by technology

In the former process route, a single dopant gas and dopant concentration are generally used to prepare TCO films. The disadvantage of this method is that the process window is narrow, and higher haze can only be obtained by increasing the thickness, which reduces TCO. The optical transmittance of the film layer increases the production cost, and the V-shaped textured structure is easy to cause structural defects such as holes and gaps in the microcrystalline silicon absorbing layer deposited later

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