Many variants of thin film technology are nowadays part of the photovoltaic market. The most popular are amorphous silicon, CIS (Copper Indium Selenide)/CIGS (Copper Indium Gallium Selenide)/CIGSS (Copper Indium Gallium Sulphur Selenide), and CdS/CdTe (Cadmium Sulphide/Cadmium-Telluride) cells. All mentioned types allow potentially for a flexible cell structure. Most emitter contacts are currently based on TCOs (Transparent Conductive Oxides), however, wider approach with alternative carbon nanoforms, silver nanolayers and polymer materials, called TCLs (Transparent Conductive Layers) are also in use. Authors decided to investigate influence of mechanical stresses on physical and electrical behaviour of these layers. Consequently, the aim of work is to determine the level and possible mechanisms of flexible a-Si cell parameters degradation due to a deterioration of transparent contact properties.

In this paper the experimental results of piezoelectric and magnetostrictive ultrasonic stimulation are comparatively analyzed in the evaluation of impact damage in a graphite epoxy composite sample chosen for a round robin test. By comparing theoretical and experimental results, it is shown that the equivalent power of internal friction can reach some hundreds mill watt per a single crack.