Mo Contact via High-Power Impulse Magnetron Sputtering on Polyimide Substrate

It has always been a huge challenge to prepare the Mo back contact of inorganic compound thin film solar cells (e.g., CIGS, CZTS, Sb2Se3) with good conductivity and adhesion at the same time. High-power impulse magnetron sputtering (HiPIMS) has been proposed as one solution to improve the properties of the thin film. In this study, the HiPIMS technology replaced the traditional DC power sputtering technology to deposit Mo back contact on polyimide (PI) substrates by adjusting the experimental parameters of HiPIMS, including working pressure and pulse DC bias. When the Mo back contact is prepared under a working pressure of 5 mTorr and bias voltage of -20 V, the conductivity of the Mo back contact is 9.9 x 10(-6) ohm center dot cm, the residual stress of 720 MPa, and the film still has good adhesion. Under the minimum radius of curvature of 10 mm, the resistivity change rate of Mo back contact does not increase by more than 15% regardless of the 1680 h or 1500 bending cycle tests, and the Mo film still has good adhesion in appearance. Experimental results show that, compared with traditional DC sputtering, HiPIMS coating technology has better conductivity and adhesion at the same time, and is especially suitable for PI substrates.

Automated summary

In this study, the HiPIMS technology was used to deposit Mo back contact on polyimide substrates, resulting in a thin film with good conductivity and adhesion. The experimental parameters of HiPIMS were adjusted to improve the properties of the film, and it was found that HiPIMS coating technology has better conductivity and adhesion compared to traditional DC sputtering. This technology is particularly suitable for PI substrates.