Hydrogenated amorphous silicon thin film solar cells are prepared using radio frequency plasma enhanced chemical
vapor deposition on polyimide substrates. The structure of the cell is polyimide /Al/n-μc-Si:H/i-a-Si:H/p-a-SiC:H/TCO.
Due to amorphous silicon cells have Staebler-Wronski effect and their efficiencies do not stabilize at prepared, so these
cells were placed more than fifteen months and I-V characteristics of these cells were measured in four times. They
include (i)in the initial, (ii) placed in desiccator over fifteen months, (iii) light-soaked for five hours under AM 1.5
(100mW/cm2) and (iv) annealed for two hours in natural conditions. The measurement results such as open-circuit
voltage, short-circuit current, resistance in series, parallel resistance, conversion efficiency and fill factor are given and
studied. Staebler-Wronski Effect are found and explained with these parameters. Generally, after light-soaking, the
short-circuit currents of cells increase, the fill factors and open-circuit voltage decrease and the reduction of the
efficiency is proportional to the fill factor. Abnormal Staebler-Wronski Effect appears in a cell. The cause of these
phenomena is analyzed. The consequence that the efficiency varieties with the fill factor is derived r. A graded gap in P-I
interface can be improved the cell efficiently. Ultimately, the stability of a-SiH thin film solar cells on polyimide
substrate is discussed.