Schulze, T.F. ; Beushausen, H.N. ; Hansmann, T. ; Korte, L. ; Rech, B.: Accelerated interface defect removal in amorphous/crystalline silicon heterostructures using pulsed annealing and microwave heating. Applied Physics Letters 95 (2009), p. 182108/1-3
10.1063/1.3255018
Abstract:
We present postdeposition annealing experiments on undoped amorphous-/n-type crystalline silicon [(i)a-Si:H/(n)c-Si/(i)a-Si:H ] heterostructures used as precursors for a-Si:H/c-Si high-efficiency solar cells. Comparing conventional hotplate- with pulsed microwave-heating we obtain excellent interface passivation and demonstrate that microwave annealing proceeds significantly faster. The effect is ascribed to the details of microwave absorption, which selectively affects Si–H bonds and thus facilitates hydrogen bond reconfiguration needed for interface passivation. Infrared absorption spectroscopy shows that the main contribution to passivation is not stemming from bulk hydrogen reconfiguration. This suggests a hydrogen-rich interface layer, whose occurrence depends on a-Si:H deposition conditions, to be responsible for the fast annealing.