Significance of tunneling in p+ amorphous silicon carbide n crystalline silicon heterojunction solar cells

• DOI: 10.1063/1.122521
• Publication Date: 2002-07-26T13:31:27Z
• Authors: M. W. M. van Cleef; R. E. I. Schropp; F. A. Rubinelli
• Keywords: 0103 physical sciences; 01 natural sciences; 7. Clean energy

We used the internal photoemission (IPE) technique to accurately determine the valence and conduction band offsets at the a-SiC:H/c-Si interface and investigated with numerical simulations their effects on the photocarrier collection in p+ a-SiC:H/n c-Si heterojunction solar cells. The valence and conduction band discontinuities were found to be 0.60 and 0.55 eV, respectively. However, despite the large barrier at the valence band edge, 30 nm p+ a-SiC:H/n c-Si heterojunction solar cells show no collection problems due to blocking of holes (FF=0.73). Combined IPE measurements and simulation results indicate that tunneling of holes through this barrier at the valence band edge can explain the unhindered collection.