MICROCRYSTALLINE SILICON FILMS AS ACTIVE LAYERS IN CRYSTALLINE SILICON SOLAR CELLS

摘要

This paper deals with the usage of microcrystalline silicon layers in large area crystalline silicon solar cells. For these tests we have developed large area (45 cm × 45 cm) deposition processes at standard frequency (13.56 MHz) for doped and undoped microcrystalline silicon (μc-Si:H) films. The doped films show low specific resistances of 1 Ohm~*cm for p-type and 0.02 Ohm~*cm for n-type layers and a high crystalline fraction of 50 - 74 % depending on the layer type. The n-type films were introduced in our common large area heterojunction process as emitter layer. First large area (n) μc-Si:H/c-Si heterojunction cells had an efficiency up to 12.5 %. The open circuit voltage of such cells could be increased by using an additional undoped amorphous silicon layer.