Process method for preparing hexagonal phase ZnS film at low temperature

Abstract

The invention relates to a process method for preparing a hexagonal phase ZnS film at low temperature. According to the process method, the characteristics of a CdS hexagonal phase structure are utilized, a CdS film layer is deposited on a sapphire substrate firstly, and the CdS is adopted and used as a buffering layer which effectively solves the problem that crystal lattices between the ZnS film and the substrate are mismatched. By utilizing the method, the growth of the hexagonal phase ZnS film is induced at low temperature, and thus the hexagonal phase ZnS film can be prepared. The technology solves the problem that the conventional chemical method is difficultly utilized for preparing the hexagonal phase ZnS film at low temperature. The ZnS / CdS alternating film layers prepared by the process method are densely adhered as well as the bottom layer and the sapphire substrate; the film is high in crystallization quality and excellent in uniformity, and the light transmittance can be more than 85%, so that the film can be used as the buffering layer of a thin-film solar cell or a material for a window; and simultaneously, the hexagonal phase ZnS film has a high luminescence peak at 500nm, so that the hexagonal phase ZnS film also can be used for developing a high-brightness green light emitting device.

Description

technical field [0001] The invention relates to a process method for preparing a hexagonal phase ZnS thin film at low temperature, belonging to the technical field of photoelectric materials. Background technique [0002] ZnS is a kind of Ⅱ-Ⅵ direct bandgap luminescent material with superior performance. It has two crystal phases, cubic and hexagonal. With characteristics, ZnS thin films are widely used in flat panel displays, thin film electro-optical devices, infrared windows, photodetectors, sensors, lasers, etc. The crystal phase structure of the ZnS thin film plays a crucial role in the physical properties of the above devices. For example: Compared with the cubic phase, the hexagonal ZnS film is more suitable to replace the CdS film as the buffer layer or window material of the CdTe thin film solar cell. However, since the more stable structure of ZnS at room temperature is the cubic phase structure, the phase transition temperature of the cubic phase to the hexagona...

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Problems solved by technology

At present, the method of preparing hexagonal ZnS thin film based on CdS thin film as buffer layer and below 200 °C has not been mentioned.

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