Study of the pinhole density in a-Ge:H and a-Ge0.9Si0.1:H thin films

Abstract The pinhole density in ion-beam sputtered a-Ge:H and a-Ge 0.9 Si 0.1 :H films was measured as a function of the hydrogen content and sample storage time. Films deposited on Corning glass substrates exhibit pinhole densities that increase with the storage time after their deposition. The average pinhole density reaches a saturation value approximately after three weeks, which is between six and several tens of pinholes per mm 2 for non-hydrogenated and hydrogenated films, respectively. The time evolution of the pinhole density seems to be associated to the local creep occurring at bubble edges, the bubbles converting into pinholes when the local strain reaches a critical value.