Preparation And Characterization Of Diffusion Barrier And Absorbing Layer For Flexible CIGS Solar Cell

Flexible substrate Cu(In,Ga)Se2 (CIGS) solar cell has many advantages, it not only has to light quality, flexible, and can use such advantages as around the belt type deposition, can realize mass production, significantly reduce the production cost. CIGS based thin-film solar cells with flexible metal substrates such as copper and stainless steel, which is low-cost, but can adapt to high-temperature preparation of the device for high-quality environment. But the spread of harmful elements in the substrate will reduce the quality of the battery, so the preparation of diffusion barriers between the substrate and the back contact is indispensable. CIGS based thin-film is beneficial to large scale production when selenylation after sputtering, and then is a better option for it's security and low requirements on environmental protection equipment. However, the current solid selenium equipment is not good for continuous rollable production. This paper focus on the low preparation of diffusion barriers on stainless steel and copper, as well as the preparation of absorber and the technic of continuous solid-state selenylation, hope to provide the basis for the industrial production . The main contents are as follows:Firstly, Ni, Ni-Mo alloy and Ni / Ni-Mo multilayer film are prepared respectively as diffusion barriers, and the preparation of Ni / Ni-Mo multilayer film were developed, the related property of diffusion barriers were investigated by SEM, EDS and other test methods. The results indicated that Ni / Ni-Mo multilayer film is appropriate diffusion barriers for CIGS based thin-film solar cells; and reduce the thickness of Ni while increase the Mo in Ni-Mo thin film can improve the role of diffusion barriers.Secondly, the Cu-In alloy prefabricated film were prepared by magnetron sputtering, the effect of power on deposition rate, surface morphology, composition and phase structure were studied. Heat treatment after sputtering under the condition of 280℃, rapid heating and 2min in non-vacuum can obtained a good phase structure.Thirdly, the selenylation stove and high activity steam supply device were designed for continuous rollable production of flexible CIGS solar cells. Cu-In alloy prefabricated film went through heating, forming absorber after selenylation and cooling in the stove chamber. The steam supply device is convenient operation, and can supply Se steam continuously.Lastly, the technology of selenium was studied by designed device, the effect of selenylation parameter as well as substrates on absorber were investigated. Multilayer on stainless steel can adapt to high temperature corrosive environment, the morphology of absorber is alike the glass substrate, and formed single CuInS₂ structure with peak 112 and peak 220/204., rapid curing at high temperature after Rapid rise to 700℃, the flow rate of carrier gas have a greater impact to absorber, high temperature curing 1min at lower flow rate can abtained the grain size exceeds 2μm and bond tightly and has a (112) preferred orientation, the stoichiometric ratio of absorber approached Cu: In: S = 1:1:2.