Fabrication of Flexible Amorphous-Si Thin-Film Solar Cells on a Parylene Template Using a Direct Separation Process

In this paper, we report on the fabrication of flexible amorphous-silicon (a-Si) thin-film solar cells on a parylene template carried by a glass plate without any adhesive. The a-Si thin-film solar cells could be separated directly from the glass carrier after a process temperature of up to 200°C. The a-Si and parylene films were deposited using high-frequency plasma-enhanced chemical vapor deposition and a parylene reactor. The parylene-coated glass plate was treated with thermal annealing and Ar, N₂, or O₂ plasma. Moreover, SiNx and/or SiOx films were used as barrier layers between the transparent conductive oxide and parylene films. Details of different gas plasmas and barrier effects were investigated in terms of surface morphologies and solar cell characteristics. The a-Si thin-film solar cell on a parylene template with an open-circuit voltage of 0.74 V, a short-circuit current density of 15.69 mA/cm², a fill factor of 54.98%, and a conversion efficiency of 5.78 % could be obtained. After the 10-mm-radius bending test for 5000 times, the a-Si thin-film solar cells still exhibited a conversion efficiency of 4.94%. These results indicated that a-Si thin-film solar cells on parylene templates have high potential for flexible photovoltaic applications.