Study of stability for a-Si:H thin-film solar cells on polyimide substrates

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.© (2007) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.