Background:

Academia and industry generally believe that solar cell development has entered its third generation. This generation of solar cells encompasses compound thin-film solar cells such as copper indium gallium selenide (CIGS) and thin-film Si-series solar cells. CIGS solar cells offer the highest conversion efficiency among thin-film solar cells and hold great potential for development. However, due to their sensitive elemental composition and complex multilayer structure, CIGS thin-film solar cells require extremely demanding preparation methods and conditions, resulting in a very slow industrialization process. Currently, the most common method for preparing CIGS thin films is selenization. The selenization process involves first smelting Cu-in-Ga into an alloy and preparing a target suitable for sputtering. A Cu-in-Ga thin film is then formed on a Mo layer through a sputtering process. Se is then heated and evaporated into a gas, causing Se atoms to deposit on the Cu-in-Ga layer and react with the Cu-in-Ga through atomic diffusion to form a GuInGaX-1Se2 compound. The disadvantages of the aforementioned "selenization" method include: long production cycles, low production efficiency, high energy consumption, the highly toxic selenium (Se) that can easily cause safety incidents, and the highly corrosive nature of gaseous Se to other metals, which can easily lead to Se vapor leaks; and uneven Se distribution in the resulting films. This method is very costly to produce CIGS solar cells. The ideal method for producing CIGS solar cells is the one-step sputtering method, which involves sputtering a pre-prepared CIGS target material in a single pass to produce a uniform CIGS thin film. CIGS targets are the foundation for producing CIGS thin films using the one-step sputtering method, while CIGS alloys are the foundation for producing CIGS targets. Currently, the industrial synthesis of CIGS targets still faces numerous challenges, such as long production cycles, low yields, unstable products, and equipment corrosion.

Technical Implementation Elements:

To address the aforementioned issues, the present invention provides a method for preparing a copper indium gallium selenide target, comprising the following steps:

1) selecting copper, indium, and gallium raw materials in a weight ratio of 8-10:23-26:7-9, crushing them into coarse powders, and mixing them uniformly;

2) jet milling the crushed coarse powders to produce a powder having a particle size of 4.5-5.5 μm;

3) placing the jet-milled mixed powders into a reactor, evacuating the reactor, and then filling the reactor with argon gas at a pressure of 0.3-0.5 MPa and a flow rate of 30-40 cc/min;

4) heating the reactor to 300-400°C and maintaining the temperature for 1-3 hours;