High-Performance and Industrially Viable Nanostructured SiOx Layers for Interface Passivation in Thin Film Solar Cells

Herein, it is demonstrated, by using industrial techniques, that a passivation layer with nanocontacts based on silicon oxide (SiOx) leads to signicantimprovements in the optoelectronical performance of ultrathin Cu(In,Ga)Se2(CIGS) solar cells. Two approaches are applied for contact patterning of thepassivation layer: point contacts and line contacts. For two CIGS growth con-ditions, 550 and 500°C, the SiOx passivation layer demonstrates positive pas-sivation properties, which are supported by electrical simulations. Such positiveeffects lead to an increase in the light to power conversion efciency value of2.6% (absolute value) for passivated devices compared with a non passivated reference device. Strikingly, both passivation architectures present similar efficiency values. However, there is a trade-off between passivation effect and chargeextraction, as demonstrated by the trade-off between open-circuit voltage (Voc)and short-circuit current density (Jsc) compared with full factor (FF). For the first time, a fully industrial upscalable process combining SiOxas rear passivationlayer deposited by chemical vapor deposition, with photolithography for linecontacts, yields promising results toward high-performance and low-costultrathin CIGS solar cells with champion devices reaching efficiency values of12%, demonstrating the potential of SiOxas a passivation material for energy conversion devices