Synthesis of T-Nb₂O₅ thin-films deposited by atomic layer deposition for miniaturized electrochemical energy storage devices

Saliha Ouendi (1, 2, 3) , Cassandra Arico (1, 4, 2, 5) , Florent Blanchard (6) , Jean-Louis Codron (2, 3) , Xavier Wallart (2, 7) , Pierre-Louis Taberna (1, 4) , Pascal Roussel (6) , Laurent Clavier (2, 5, 8) , Patrice Simon (1, 4) , Christophe Lethien (1, 2, 5)

1 RS2E - Réseau sur le stockage électrochimique de l'énergie
2 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
3 CMNF - IEMN - Centrale de Micro Nano Fabrication - IEMN
4 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
5 CSAM - IEMN - Circuits Systèmes Applications des Micro-ondes - IEMN
6 UCCS - Unité de Catalyse et Chimie du Solide - UMR 8181
7 EPIPHY - IEMN - EPItaxie et PHYsique des hétérostructures - IEMN
8 CERI SN - IMT Nord Europe - Centre for Digital Systems

Atomic Layer Deposition has been used to grow 30 to 90 nm-thick amorphous Nb₂O₅ films onto Pt current collectors deposited on Si wafer. While T-Nb₂O₅ polymorph is obtained by further annealing at 750 °C, the film thickness and the resulting electrode areal capacity are successfully controlled by tuning the number of ALD cycles. The electrochemical analysis reveals a lithium ion intercalation redox mechanism in the T-Nb₂O₅ electrode. An electrode areal capacity of 8 µAh.cm^-2 could be achieved at 1 C, with only 40% capacity loss at 30 C (2 minutes discharging time). This paper aims at demonstrating the use of Atomic Layer Deposition method in the fabrication of Nb₂0₅-based on-chip micro-devices for Internet of Things (IoT) applications.

Mots clés: Atomic Layer Deposition; Nb2O5; Micro-devices; Surface capacity

Domaines: Matériaux; Sciences de l'ingénieur [physics]

Saliha Ouendi, Cassandra Arico, Florent Blanchard, Jean-Louis Codron, Xavier Wallart, et al.. Synthesis of T-Nb₂O₅ thin-films deposited by atomic layer deposition for miniaturized electrochemical energy storage devices. Energy Storage Materials, 2019, 16, pp.581-588. ⟨10.1016/j.ensm.2018.08.022⟩. ⟨hal-02135683⟩