Enhanced performance of amorphous silicon solar cells (110 °C) on flexible substrates with a-SiC:H(p) window layer and H2 plasma treatment at n/i and i/p interface

Abstract

The a-Si:H based n-i-p solar cells were fabricated on flexible polyethylene terephthalate (PET), polyimide (PI) and rigid glass substrates with a-SiC:H(p) as a window layer using radio frequency plasma enhanced chemical vapor deposition technique. The effect of methane flow rate (MFR) on the structural and optoelectronic properties of a-SiC:H(p) films deposited at a low substrate temperature (Ts) 110 °C were studied on Corning 1737 glass (glass) substrate. The influence of hydrogen plasma treatment (HPT) at n/i and i/p interface of solar cells was also investigated. The HPT at interfaces was found to minimize interface defects and enhance the optical and electrical properties of the solar cell. The solar cell with a-SiC:H(p) as a window layer with HPT at interfaces have shown improvement in the series resistance (Rs), shunt resistance(Rsh), open circuit voltage (Voc) and fill factor (FF) as compared to the solar cells fabricated with conventional a-Si:H(p). The efficiencies of fabricated solar cell at 110 °C on flexible PET and PI are 3.36 and 4.06%, which is close to 4.42% on rigid glass. Our results demonstrate that, a-SiC:H(p) as a window layer with HPT at n/i and i/p interfaces can be considered as a practical method to produce the a-Si:H based solar cells on low cost flexible substrates at low substrate temperature.