Schulze, T.F.; Beushausen, H.N.; Leendertz, C.; Dobrich, A.; Hannappel, T.; Korte, L.; Rech, B.: Impact of a-Si:H structural properties on the annealing behavior of a-Si:H/c-Si heterostructures used as precursors for high-efficiency solar cells. In: Friedman, D... [Ed.] : Defects in inorganic photovoltaic materials : Spring 2010, April 5 - 9, San Francisco, California, U.S.A.Warrendale: MRS, 2010 (Materials Research Society symposium proceedings ; 1268). - ISBN 978-1-605-11245-9, p. 1268-EE01-07
10.1557/PROC-1268-EE01-07
Abstract:
We analyze the dependence of the interface defect density Dit in amorphous/crystalline (a-Si:H/c-Si) heterostructures on the microscopic properties of the ultrathin (10nm) undoped a-Si:H films. It is shown that the hydrogen bonding configuration, probed by infrared spectroscopy, determines the a-Si:H network disorder, which in turn governs the annealing behavior of these structures upon a short thermal treatment at moderate temperatures (T = 200°C). While the as-deposited Dit seems to be determined by the local structure at the interface, the final state of the annealed samples is determined by the bulk a-Si:H network strain as reflected in the valence band tail slope. Thus it appears valid to treat the equilibrated a-Si:H/c-Si interface as a 2D-layer that has the projected defect properties of the 3D a-Si:H bulk.