TCO contacts for high efficiency c-Si solar cells: Influence of different annealing steps on the Si substrates and TCO layers properties

Abstract

Different Transparent Conductive Oxide (TCO) layers properties are evaluated after annealing steps at temperatures above 200°C, in order to study their potential use in crystalline silicon (c-Si) solar cells fabrication processes. While the conductivity of Indium Tin Oxide (ITO) layers obtained by magnetron sputtering (MS) is almost stable after annealing in air, Aluminum doped Zinc Oxide (AZO) layers deposited by Atomic Layer Deposition (ALD) need a controlled atmosphere to maintain high carrier densities and mobilities. During the annealing processes, contaminating atoms (such as Zn) diffuse into the c-Si bulk and may potentially decrease its quality. Thus, both the contamination of the c-Si bulk and the properties of the AZO layer have been analyzed. ; This project has received funding from the European Union (EU) Horizon 2020 research and innovation programme under grant agreement No 727529.