Intrinisic reliability of amorphous silicon thin film solar cells

In this paper, we have discussed three intrinsic reliability issues of thin-film -Si:H solar cells; space charge limited shunt conduction through localized metal-semiconductor-metal structures; shadow degradation in series connected cells in a module, and light induced degradation. Despite their distinct external manifestation, these intrinsic reliability issues appear to share common physical phenomena. For example, the light induced and the shadow degradation may be related because they are described by very similar time-exponents (see Fig. 4c and 6a). While the physics of G are different (e.g. photon induced dissociation for LID and (possibly) electron-hole recombination induced dissociation for shadow degradation), it is likely that they both break SiH bonds and are subsequently follow similar diffusive kinetics. Finally, analogies to CMOS reliability; e.g., shunt conduction related to non uniform conduction through oxides, shadow degradation to bulk defect generation and TDDB in gate dielectric, and light induced degradation to NBTI in PMOS transistors; may help illuminate many aspects of the degradation processes.