APPLICATION OF ELECTRON-BEAM TESTING TECHNIQUE TO POTENTIAL PROFILE MEASUREMENT IN A-SI-H SOLAR-CELLS AT VARIOUS STATES OF OPERATION

The electron-beam testing (EBT) technique was used to determine the de pth profile of the internal potential in an a-Si:H solar cell and henc e the internal electric field profile. The a-Si:H solar cells were pre pared for the EBT measurements by etching small wells of varying depth s into the p-i-n layers by means of a plasma beam through a mask struc tured by electron-beam lithography (EBL). In contrast to earlier work [5] the solar cells were not only investigated in various electrical s tates of operation but also under illumination at various wavelengths and intensities and at different temperatures, including in situ annea ling of degraded cells. It was demonstrated for these thin-film solar cells that by combining EBT with a suitable micro-structuring preparat ion method (EBL and plasma-beam etching) the depth dimension was opene d up to EBT.