Interface recombination via a hetero-interface is frequently the main loss mechanism in heterojunction solar cells. Interface recombination is determined mainly by:
The absorber bend bending (the position of the Fermi energies at the interface)
The effective interface recombination of an a-Si:H/c-Si structure can be measured by monitoring the transient decay of the absorber excess carrier density, if one excites the structure exclusively in the c-Si absorber. Thus the effective decay time constants of the absorber can be determined. Fig. 1 shows the transient SPV(t) decay of a-Si:H/c-Si heterostructures, with differently deposited a-Si:H emitters.