Carbon based Materials
Seminconductors, Oxides and Chalcogenides
Chalcogenide alloys are a fascinating group of materials that have garnered significant attention for their application in phase change memories (PCM) thanks to their ability to switch between amorphous and crystalline states with the application of heat or electrical current.
Chalcogenide alloys are typically composed of elements from the chalcogen group such as sulfur, selenium, and tellurium, combined with other elements like germanium, antimony, or arsenic and exhibit unique properties that make them ideal for non-volatile memory storage.
This reversible phase transition is accompanied by a dramatic change in electrical resistance, which is exploited to represent binary data. As research and development continue, these materials may pave the way for faster, more efficient, and more durable memory systems, revolutionizing how we store and access information in the digital age.
Chalcogenides containing Ge, Sb, Te and Transition Metal Dichalcogenides (TDMCs) are obtained (at CNR-IMM Rome) by Radio Frequency sputtering: this is a Physical Deposition technique for producing high-quality films on low-temperature substrates.
The technique is cost-effective and flexible, allowing for the deposition of layered materials with precise control over refractive index and thickness.
In addition, chalcogenide materials composed of thin films and nanowires of the system (Bi, Sb, Te) can be obtained (in collaboration with CNR-IMM Agrate Brianza) with the MOCVD (metalorganic chemical vapor deposition) synthesis.
MOCVD is a Chemical Deposition technique used to create single or polycrystalline thin films. It can grow crystalline layers to form complex semiconductor multilayer structures.
In MOCVD, ultrapure precursor gases are injected into a reactor. The gases undergo thermal decomposition as they approach the substrate (such as a silicon wafer), leading to the deposition of materials on it. The applications are in the field of devices with properties of PCM, topological insulators (acting as an electrical insulator in its bulk form but allows electrical conduction to occur on its surface, leading to magnetoelectronic and optoelectronic devices) and thermoelectric materials (in which a temperature gradient can lead to the generation of an electric voltage, and conversely, an electric current can induce a temperature gradient).
Many analysis tools complement the synthesis of the above materials, including the study of their morphological, structural, compositional and functional properties.