2134/27450 Piotr M. Kaminski Piotr M. Kaminski Sibel Yilmaz Sibel Yilmaz Ali Abbas Ali Abbas Francesco Bittau Francesco Bittau Jake Bowers Jake Bowers Rachael Greenhalgh Rachael Greenhalgh Michael Walls Michael Walls Blistering of magnetron sputtered thin film CdTe devices Loughborough University 2017 CdTe Thin film Solar cell Magnetron sputtering Photovoltaics Electron microscopy Working gas Mechanical Engineering not elsewhere classified 2017-11-16 10:14:12 Conference contribution https://repository.lboro.ac.uk/articles/conference_contribution/Blistering_of_magnetron_sputtered_thin_film_CdTe_devices/9557576 Magnetron sputtering is an industrially scalable technique for thin film deposition. It provides excellent coating uniformity and the deposition can be conducted at relatively low substrate temperatures. It is widely used in the manufacture of solar modules. However, its use for the deposition of thin film CdTe devices results in unusual problems. Blisters appear on the surface of the device and voids occur in the CdTe absorber. These problems appear after the cadmium chloride activation treatment. The voids often occur at the CdS/CdTe interface causing catastrophic delamination. This problem has been known for more than 25 years, but the mechanisms leading to blistering have not been understood. Using High Resolution Transmission Electron Microscopy we have discovered that during the activation process, argon trapped during the sputtering process diffuses in the lattice to form gas bubbles. The gas bubbles grow by agglomeration particularly at grain boundaries and at interfaces. The growth of the bubbles eventually leads to void formation and blistering.