Nanotechnology Chemistry Laboratory (NanoChemLab) is affiliated to CNRS and UM and is located at the Electronic Institute of Montpellier (IES) within the Saint Priest campus, which includes renowned centers in sensors devices, materials science, microelectronics and robotics, among others.
NanoChemLab develops a new theme dedicated to the synthesis and integration of novel functional oxides nanomaterials by chemical solution deposition (CSD) for the design of new innovative sensors. This interdisciplinary lab at the interface between soft chemistry and microfabrication techniques addresses a range of skills and resources ranging from the synthesis of 1D, 2D and 3D functional oxides nanostructures to the design of sensors and harvesting energy devices, through advanced structural characterizations at the nanoscale.
We are fascinated by the growth mechanisms of novel integrated oxide components on silicon and other technological substrates by large scale, green and low cost chemical routes. We develop different approaches including the growth of nanostructured oxides entirely performed by chemical solutions and the combination of soft chemistry with other prominent physical methodologies in microelectronics like Molecular Beam Epitaxy (MBE) or Chemical Vapor Deposition (CVD).
Among the rich and varied properties of oxides, piezoelectricity can produce electricity from deformations or frictions generated by mechanical excitations. The piezoelectric effect translates the charge asymmetry produced in the interior of a material when it is deformed into an electric field typically exploited in harvesting energy devices.
On the other side, piezoelectric oxides can also be used for sensor applications where the direct piezoelectric effect (i.e. the generation of electrical charge by an applied stress) is used as a sensing mechanism and operates in different sensing modes including compression, shear, and flexural mode. As a consequence, piezoelectric materials might provide solutions to many technological challenges including lower energy consumption devices and inertial sensors for distance, movement and acceleration detection. In this direction, integrating high quality epitaxial piezoelectric films and nanostructures on silicon could booster the fabrication of a number of devices with the traditional Si-based complementary metal-oxide-semiconductor (CMOS) technology.
Moreover, advances in micro and nanofabrication technologies, open the possibility to implement a large-scale integration of miniaturized piezoelectric materials into innovative electromechanical devices with nanosized moving parts (MEMS / NEMS) with prospective applications in electronics, biology and medicine.
Nanochemlab research project at the IES is particularly interested on the epitaxial growth of nanostructured piezoelectric and ferroelectric oxides films on silicon, relevant to integrate sensing and harvesting energy functionalities in MEMS and other resonant systems.
In the last 5 years, Nanochemlab contributed significantly to the epitaxial integration and application of different piezoelectric functional oxides in 1D, 2D and 3D forms on silicon substrate. For the first time, we successfully established direct and hybrid soft chemistry routes to prepare: (i) mesoporous, textured and dense epitaxial 1D and 2D quartz thin films, (ii) 1D nanostructured epitaxial fonctional hollandite complex oxide thin films, and (iii) nanostructured and dense epitaxial lead free ferroelectric perovskite oxide heterostructures on silicon wafers.
Following up with these findings, Nanochemlab choses the chemical solution integration of epitaxial piezoelectric and ferroelectric oxide thin layers on silicon and silicon–insulator–silicon (SOI) substrates with high-performance piezoelectric response. This includes epitaxial α-quartz, hollandite and perovskite oxide films, 1D wires, or rods to enhance its performance. The overall objective of Nanochemlab scientific project is to develop new resonator multisensors for monitoring mechanical parameters (mass, forces, pressure, torque, etc.) and novel nanogenerators to harvest vibrational energy based on these nanostructured piezoelectric oxides.
To address these objectives, Nanochemlab apply an interdisciplinary approach based on four main technical developments:
- Development of a Chemical Solution Platform for a global integration methodology of functional oxides on silicon. These oxides must be abundant, non-toxic and environmentally friendly materials (e.g. tellurium-free, lead-free materials), produced by low-cost and scalable techniques, so that affordable devices can be made available in very large quantities.
- Development of cost-efficient and scalable micro and nanostructuration techniques of piezoelectric thin films.
- Development of an advanced physical and structural characterization platform of epitaxial piezoelectric nanostructures and thin films.
- Bridge the gap between chemical material development and device fabrication. For lowering material and energy fabrication budgets, and to reduce power consumption while operating.