CuInS2 thin film and preparation process thereof

Abstract

The invention provides a CuInS2 thin film and a preparation process thereof, and relates to the technical field of thin film materials. The stoichiometric ratio of each component of the thin film is close to an ideal stoichiometric ratio; the thin film is flat in appearance, uniform in thickness and compact in tissue; and a forbidden bandwidth of the thin film is close to the optimal forbidden bandwidth of an ideal solar cell photoelectric material; the stoichiometric ratio of the components of the film is Cu: In: S (at%) = 1: 1.082: 1.965; the grain size is 0.4 to 1.3 micros; the forbidden bandwidth Eg is 1.459 eV; a constant-potential one-step electro-deposition method is adopted for preparation, and a Cu-In-S three-electrode system and sulfate system electrolyte are adopted during electro-deposition; and the electrolyte comprises copper sulfate, indium sulfate, sodium thiosulfate, potassium hydrogen phthalate, lauryl sodium sulfate and water. The technical scheme is suitable for thepreparation process of the CuInS2 thin film.

Description

【Technical field】 [0001] The invention relates to the technical field of thin film materials, in particular to a CuInS 2 Thin film and its preparation process. 【Background technique】 [0002] CuInS 2 It is a group I-III-IV direct bandgap semiconductor compound. It has a high light absorption coefficient (10 5 cm -1 ), the bandgap width (1.50eV) is closer to the optimal bandgap width (1.45eV) required by the solar cell, the corresponding photovoltaic device has no light decay effect, and the theoretical value of the photoelectric conversion rate reaches 28-32%. Therefore CuInS 2 It is one of the most promising materials for the light absorbing layer of thin film solar cells. [0003] CuInS 2 There are many methods for preparing thin films, including vulcanization method, vacuum multiple evaporation method, atomic layer deposition method, spray pyrolysis method, radio frequency sputtering method, molecular beam epitaxy method, ion layer gas phase reaction method, chemic...

AI Technical Summary

Problems solved by technology

[0005] The existing one-step electrodeposition process usually uses a chloride-based electrolyte, but it is highly corrosive, and if it is not properly controlled, chlorine gas will be precipitated on the surface of the cathode material, causing trouble

In addition, because the chloride ion reduces the cathode polarization and activates the electrode reaction, the obtained film is relatively rough and has poor flatness.

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