System for manufacturing complete Cu(In,Ga)Se2 solar cells in situ under vacuum

We present the development of a small foot-print physical vapor deposition (PVD) system for in-situ deposition of all layers required in a complete Cu(In,Ga)Se (CIGS) solar cell. Seven sputtering magnetrons and one valved-cracker source have been custom designed and manufactured for this system, named SpuTtering for Advanced Research (STAR). The purpose of STAR is to develop a technique to fabricate a complete CIGS solar cell, including contacts, absorber, buffer, and window layers, under high vacuum with the aim to transfer this technology to a future industrial production line. The system's capabilities and its relatively high throughput place it somewhere in between research and industrial development levels. It is possible to work on the deposition of the back contact, the CIGS absorber, and the window layer of three solar cells simultaneously. Calibration data, selection of parameters for the deposition of the individual layers, and initial results of a complete CIGS solar cell developed with STAR are reported.
We acknowledge financial support by the Spanish projects AIC-B-2011-0806 and MAT2015-67021-R, and by the “Micro-concentrator thin film solar cells (MiconCell)” project (028922), and the “Correlated Analysis of Inorganic Solar Cells in and outside an Electron Microscope (CASOLEM)” project (028917), both co-funded by FCT and the ERDF through COMPETE2020. We also acknowledge financial support by MCIU-AEI-FEDER-UE (ENE2017-91092-EXP, RTI2018-096937-B-C22) and Comunidad de Madrid (P2018/EMT-4308). We acknowledge the services at IMN-CNM from the X-SEM Laboratory (MINECO CSIC13-4E-1794) and from MiNa Laboratory (funding from CM under project S2013/ICE-2822, Space-Tec) both with support from EU (FEDER, FSE)”.