Materials, microelectronics, acoustics, nanotechnologies (GREMAN)

GREMAN specializes in materials, components and systems for electrical energy management and conversion with the aim to improve energy efficiency. Thanks to the knowledge of its four teams, which deal both with materials sciences (solid-state physics and chemistry) and engineering sciences (microelectronics, ultrasounds, electrical engineering), it can carry out work from the synthesis of new materials with remarkable properties to the development of components and devices and their integration in electrical systems.

Applications range from new microelectronics components, both active and passive, transducers and ultrasound systems, systems for electrical energy conversion.

Its research activities include fundamental studies involving simulation tools and models developed within the laboratory. They benefit from a range of technological platforms including the CERTeM (Centre d’Etudes et Recherches Technologiques en Microélectronique) for multiphysics and multiscale fabrication and characterization.

Research topics:

Functional oxides for energy efficiency: combinatorial synthesis & nanostructuration

The main goals are the development of new synthesis paths and the structuration of functional oxides, cheaper, greener and stable in time, with properties improving energy efficiency. The detailed study of their properties evolving with composition, dimensions, and interfaces (single crystals, thin films, bulk ceramics, nano powders, nanowires …) is a specialty.

Magnetic and optical properties of ferroic materials with electronic correlations:

The remarkable properties of many materials are related to electronic correlations and competing interactions that make them. They are studied by combining optical spectroscopy technics, magnetic measurements, and numerical simulations, allowing an understanding of the mechanisms responsible for the behavior of materials such as multiferroics or Mott Insulators to name but a few.

Ultrasonic devices and characterizations

The expertise acquired on capacitive and piezoelectric ultrasound transducers technologies is implemented to design innovative devices such as high frequency probes for high-resolution medical imaging and high-density transducer networks. Ultrasound waves are also a preferred way for a non-destructive investigation of complex structures and mediums while developing new investigation strategies.

Energy, components, systems, microelectronics

The strength is the conception of original devices fulfilling the future needs of mobile and power electronics. Main activities focus on porous semiconductors and wide band gap materials (SiC, GaN, ZnO) for microelectronics and vibration energy harvesting. Furthermore, these abilities are used for the development of macroscopic systems for electrical energy conversion and management.

Experimental tools:

• Clean rooms 2100 m² (ISO 5, 7 and 8), lithography, sputtering (PVD, PLD, LPCVD, PECVD, ALD), plasma etching (RIE, IBE), ion implantation, annealing (RTA, high temperature, laser).
• Synthesis of powders, ceramics (Spark Plasma Sintering), single crystals (optical furnace).
• Electron microscopy (SEM, TEM, AFM, FIB-STEM), spectroscopy (IR, visible, Raman), EPR, X-ray diffraction, ellipsometry, dilatometry, PPMS.
• Interferometry and laser vibrometry, holography.
• Electrical measurements (DC and RF probe stations, anechoic chamber).
• Acoustic measurements (microscopy, immersed and automatized systems).