Rapid laser-induced low temperature crystallization of thermochromic VO2 sol-gel thin films

DOI: 10.1016/j.apsusc.2023.157507

Authors: Maria Basso (University of Padova and INSTM; University College London (UCL)) , Elena Colusso (University of Padova and INSTM) , Chiara Carraro (University of Padova) , Curran Kalha (University of Padova) , Aysha A. Riaz (University College London) , Giada Bombardelli (University of Padova and INSTM) , Enrico Napolitani (University of Padova) , Yu Chen (Monash University) , Jacek Jasieniak (Monash University) , Laura E. Ratcliff (University of Bristol) , Pardeep K. Thakur (Diamond Light Source) , Tien-Lin Lee (Diamond Light Source) , Anna Regoutz (University College London) , Alessandro Martucci (University of Padova and INSTM)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Applied Surface Science , VOL 2

State: Published (Approved)
Published: May 2023
Diamond Proposal Number(s): 29451

Abstract: The thermochromic properties of vanadium dioxide (VO2) offer great advantages for energy-saving smart windows, memory devices, and transistors. However, the crystallization of solution-based thin films at temperatures lower than 400°C remains a challenge. Photonic annealing has recently been exploited to crystallize metal oxides, with minimal thermal damage to the substrate and reduced manufacturing time. Here, VO2 thin films, obtained via a green sol-gel process, were crystallized by pulsed excimer laser annealing. The influence of increasing laser fluence and pulse number on the film properties was systematically studied through optical, structural, morphological, and chemical characterizations. From temperature profile simulations, the temperature rise was confirmed to be confined within the film during the laser pulses, with negligible substrate heating. Threshold laser parameters to induce VO2 crystallization without surface melting were found. With respect to furnace annealing, both the crystallization temperature and the annealing time were substantially reduced, with VO2 crystallization being achieved within only 60 s of laser exposure. The laser processing was performed at room temperature in air, without the need of a controlled atmosphere. The thermochromic properties of the lasered thin films were comparable with the reference furnace-treated samples.

Journal Keywords: vanadium oxide; sol gel; laser; thermochromic; smart windows; photonic curing

Diamond Keywords: Smart Windows

Subject Areas: Materials, Physics


Instruments: I09-Surface and Interface Structural Analysis

Added On: 19/05/2023 23:15

Discipline Tags:

Surfaces Physics Electronics Materials Science interfaces and thin films

Technical Tags:

Spectroscopy X-ray Photoelectron Spectroscopy (XPS) Hard X-ray Photoelectron Spectroscopy (HAXPES)