Stability of deuterated amorphous silicon solar cells

In order to elucidate the microscopic mechanism for the earlier observed enhanced stability of deuterated amorphous silicon solar cells we conducted a side-by-side study of fully deuterated intrinsic layers on crystalline silicon substrates using the free-electron laser facility at Nieuwegein (FELIX) to resonantly excite the Si–D stretching vibration and measure the various relaxation channels available to these modes, and of p-i-n solar cells with identical intrinsic absorber layers on glass/TCO substrates to record the degradation and stabilization of solar cell parameters under prolonged light soaking treatments. From our comparative study it is shown that a-Si:D has a superior resistance against light-induced defect creation as compared to a-Si:H and that this can now be explained in the light of the `H collision modelʹ since the initial step in the process, the release of H, is more likely than that of D. Thus, a natural explanation for the stability as observed in a-Si:D solar cells is provided.