Surface recombination in oxide passivated silicon solar cells investigated by quasistatic capacitance voltage curves of Al/SiO_2/p-Si MOS capacitors under illumination. Preprint Conference paper

In this paper the quasistatic (QS) and high frequency (HF) capacitance voltage (CV) method are applied on Al/SiO_2/p-Si MOS capacitors for characterisation of the SiO_2/Si interface. The QS CV curves are recorded in the dark and under various illumination levels. We find that conventional analysis of interface state distribution leads to contradictious results for the QS and the HF CV curves, respectively. Furthermore, the QS CV curves under illumination show a distinct sharp peak which cannot result from interface states. It is that all these features can be consistently explained with a model, which considers surface states as well as near-interface oxide states interacting with the space charge region via tunneling processes. The capture cross section ratio #sigma#_p/#sigma#_n of interface states required by the model agrees with data obtained from deep level transient spectroscopy. We believe that near-interface oxid states contribute significantly to the net surface recombination velocity and confirm this by correlation of the modeled oxide trap density with independently measured effective minority carrier lifetime. (orig.)Available from: http://www.isfh.de/institut/publika/glasgow.htm / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman