A new approach to the effective use of intrinsic a-Si:H in thin film solar cells

A solar cell junction symbolized as P+-i-N+ is examined in which amorphous silicon hydride is placed between two heavily doped, wide bandgap semiconductors. A potential barrier exists at each semiconductor interface and charge transport through the barriers occurs predominantly by tunnelling. This cell structure produces both a large built- in potential across the absorber and an increase in the average lifetime and velocity of the photogenerated carriers. Simulation of P+-i-N+ and p-i-n junctions were performed using the AMPS-1D program and the calculated conversion efficiencies were 10.0% versus 7.5%, respectively.