Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1484639 | Journal of Non-Crystalline Solids | 2008 | 12 Pages |
Electrical transport and recombination mechanisms in hydrogenated amorphous silicon, a-Si:H, are determined by localized band-tail states and deep defects. At low temperatures (T < 100 K) the photoluminescence originates from tunneling recombination between localized band-tail states and the photoconductivity arises from hopping in the band tail. This review describes the present understanding of transport and recombination mechanisms in this low-temperature regime with a focus on two aspects: (i) the kinetics of carrier recombination and the competition between geminate and non-geminate recombination, and (ii) the microscopic identification of recombination paths by magnetic resonance techniques and the proof of excitonic recombination. Inspite of its complex nanocrystalline morphology, hydrogenated microcrystalline silicon, μc-Si:H, behaves in many respects similarly to a-Si:H in that the low-temperature properties are also determined by disorder-induced localized band-tail states.