Al2O3 thin films deposited by thermal atomic layer deposition: Characterization for photovoltaic applications

Corina Barbos (1) , Danièle Blanc-Pélissier (1) , Alain Fave (1) , Claude Botella (2) , Philippe Regreny (2) , Geneviève Grenet (2) , Elisabeth Blanquet (3) , Alexandre Crisci (3) , Mustapha Lemiti (1)

1 INL - PV - INL - Photovoltaïque
2 INL - H&N - INL - Hétéroepitaxie et Nanostructures
3 SIMaP - Science et Ingénierie des Matériaux et Procédés

Al2O3 thin films with thickness between 2 and 100 nm were synthetized at 250°C by thermal atomic layer deposition on silicon substrates. Characterizations of as-deposited and annealed layers were carried out using ellipsometry, X-ray reflectivity and X-ray photoelectron spectroscopy. A silicon-rich SiOx layer at the interface between Si and Al2O3 was introduced in the optical models to fit the experimental data. Surface passivation performances of Al2O3 layers deposited on n-type float-zone monocrystalline silicon were investigated as a function of thickness and post-deposition annealing conditions. Surface recombination velocity around 2 cm.s-1 was measured after the activation of the negative charges at the Si/ Al2O3 interface under optimized annealing at 400°C for 10 min. The evolution of the interface layer and of the material properties with the thermal treatment was studied.

Mots clés: Thin films; Surface passivation; Al2O3; Atomic layer deposition; Interface characterization

Domaines: Matériaux

Corina Barbos, Danièle Blanc-Pélissier, Alain Fave, Claude Botella, Philippe Regreny, et al.. Al2O3 thin films deposited by thermal atomic layer deposition: Characterization for photovoltaic applications. Thin Solid Films, 2016, 617 (Part B), pp.108-113. ⟨10.1016/j.tsf.2016.02.049⟩. ⟨hal-01712453⟩