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

M. V. Cunha, José [INL – International Iberian Nanotechnology Laboratory, Braga, Portugal] Oliveira, Kevin [INL – International Iberian Nanotechnology Laboratory, Braga, Portugal] Lontchi Jioleo, Jackson [UCL] S. Lopes, Tomás [INL – International Iberian Nanotechnology Laboratory, Braga, Portugal] A. Curado, Marco [INL – International Iberian Nanotechnology Laboratory, Braga, Portugal] R. S. Barbosa, João [INL – International Iberian Nanotechnology Laboratory, Braga, Portugal] Vinhais, Carlos [INL – International Iberian Nanotechnology Laboratory, Braga, Portugal] Chen, Wei-Chao [Ångström Laboratory, Solid State Electronics, Ångström Solar Center, Uppsala University, Uppsala, Sweden] Borme, Jérôme [INL – International Iberian Nanotechnology Laboratory, Braga, Portugal] Fonseca, Helder [INL – International Iberian Nanotechnology Laboratory, Braga, Portugal] Gaspar, João [INL – International Iberian Nanotechnology Laboratory, Braga, Portugal] Flandre, Denis [UCL] Edoff, Marika [Ångström Laboratory, Solid State Electronics, Ångström Solar Center, Uppsala University, Uppsala, Sweden] G. Silva, Ana [Departamento de Física, Faculdade de Ciências e Tecnologia, CEFITEC, Universidade Nova de Lisboa, Campus de Caparica, Lisbon, Portugal] P. Teixeira, Jennifer [INL – International Iberian Nanotechnology Laboratory, Braga, Portugal] A. Fernandes, Paulo [INL – International Iberian Nanotechnology Laboratory, Braga, Portugal; i3N, Universidade de Aveiro, Campus Universitário de Santiago, Aveiro, Portugal] M. P. Salomé, Pedro [INL – International Iberian Nanotechnology Laboratory, Braga, Portugal; Departamento de Física, Universidade de Aveiro, Campus Universitário de Santiago, Aveiro, Portugal] et al.[show all]

Herein, it is demonstrated, by using industrial techniques, that a passivation layer with nanocontacts based on silicon oxide (SiOx) leads to signicantimprovements 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 efciency 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.