Localisation of front side passivating contacts for direct metallisation of high-efficiency c-Si solar cells.

In this work, we present the development of passivating contacts based on thin interfacial oxide/doped poly-silicon for two side contacted c-Si solar cells. In the first part, we discuss our layer optimization towards direct metallisation, using firing through of Ag-paste screen printed on a silicon nitride (SiN x :H). By optimising the poly-silicon thickness, we obtain solar cells with open circuit voltage (V OC) up to 700 mV and fill factor (FF) up to 78%. However, such results were obtained by using layers with a thickness of 95 nm, strongly limiting the short circuit current density. To overcome this limitation, we present in the second part an approach for localization of the front side passivating contact by means of deposition through a shadow mask. Finally, in the third part, we demonstrate high-efficiency c-Si solar cells with promising efficiency above 21.7% with a V OC of ∼711 mV, a high FF of 79.7% and a potential for efficiency >22%. • Thin and transparent front side passivating contacts with thicker regions of metallisation. • One single firing step for paste contacting and hydrogenation of front passivating contact. • Low degradation in locally thickened front metallized area with high V OC >710 mV. • Excellent electrical transport with FF >79.5%. [ABSTRACT FROM AUTHOR]