Absence of carrier recombination associated with the defect pool model in intrinsic amorphous silicon layers: Evidence from current–voltage characteristics on p–i–n and n–i–p solar cells

Forward bias current–voltage characteristics (JD – V) were studied for both p – i – n ~superstrate! and n – i – p ~substrate! (a-SiC:H p)/(a-Si:H i) solar-cell structures having different p/i interface layers and different thickness i-layers. Contributions of the p/i interfaces to the JD – V characteristics were separated, and the dependence on the thickness of the i-layers was established. Equivalence was observed in a comparison of the characteristics of p – i – n and n – i – p cells. The various JD – V characteristics are found to be consistent with uniform densities of defects in the i-layers, and thus inconsistent with the spatially varying large densities of defects predicted for solar-cell structures by the defect pool model. © 2003 American Institute of Physics. @DOI: 10.1063/1.1571985#