Evaluation of passivation layers via temperature-dependent lifetime measurements

The effect of temperature on the surface passivation of p-type and n-type monocrystalline silicon is evaluated by temperature dependent photoconductance decay (PCD). Wafers with different passivation layers, i.e. a-Si and SiN_x are the subject of these studies. A characteristic lifetime increment is observed for p-type samples coated with a-Si(i) when compared to substrates passivated with SiN_x, in agreement with previous literature reports. A different behavior is measured for the case of n-type samples, which show comparable lifetimes among samples with different passivation layers. An interesting lifetime increment is also found at high injection levels for n-type substrates coated with a-Si(i).