Keywords: Perovskite Solar Cell (PSC), Solid State Electrochromic (EC) Devices, Quantum dot Solar Cell (QDSC), Smart Windows, GaN Technology, Spintronic Devices, Nano-electronics, High Quality Microcavities, Wearable Printed Electronics, Charge Transport,Time of Flight (TOF), Charge Extraction by Linearly Increasing Voltage (CELIV), Thermally Stimulated Current (TSC)
The research lines of the Advanced Devices area are listed below:
- Renewable energy and energy saving devices
- Miniaturized electronic and optoelectronic devices
- ELectrical and PHOto-electrical characterization (ELPHO) - Joint Lab of CNR IMM & CNR Nanotec
Keywords: Perovskite Solar Cell (PSC), Solid State Electrochromic (EC) Devices, Quantum dot Solar Cell (QDSC), Smart Windows
The new frontier of materials science and advanced devices is represented by the latest generation nanotechnologies that are used in the design, engineering of eco-friendly hybrid organic/inorganic materials and their controlled assembly in low energy consumption micro/nanostructured active optoelectronic devices. They bring an important advancement in the environmental field for energy production from renewable sources and energy saving.
Different types of devices are implemented at the NANOTEC Institute:
The latest generation photovoltaic cells based on hybrid halide perovskites have achieved in a few years, light conversion efficiency of over 25% with good durability, exceeding the maximum efficiency currently achieved for thin film devices. Fundamental in this context is the control of the growth conditions of the polycrystalline film in order to obtain high efficiency and stable devices. For the electrodes we study alternative materials to Indium Tin oxide (ITO) based on graphene.
Quantum Dot intermediate band solar cell based on III–V Semiconductorare the subject of intense theoretical and experimental debate as they represent the possibility to overcome the thermodynamic limit of theoretical efficiency predicted by the Schockley-Queisser model for single junction cells. The use of epitaxially grown quantum dots in the III/V semiconductor system is strategic in this application as the energy levels on which this concept is based can be engineered by modifying the structural, morphological and compositional properties of these nanostructures.
Electrochromic (EC) and multifunctional solid state devicesi.e the class of devices able to modulate the amount of solar radiation passing through them selectively and independently in the visible and infrared range through the application of an electric field and using an appropriate active material, are included in the class of "green" nanotechnology for applications in "Building Integration".
Combining the functionalities of energy production, lighting and controlled shielding, through the use of low consumption lighting sources (OLEDs, perovskite LEDs -PeLEDs), solid state electrochromic (EC) devices and organic and hybrid photovoltaic (PV) cells, "smart" and self-sustainable multifunctional devices can be implemented.
Keywords: GaN Technology, Spintronic Devices, Nano-electronics, High Quality Microcavities, Wearable Printed Electronics
CNR Nanotec develops novel functional semiconducting materials to be exploited in advanced devices for photonics, sensing, diagnostics and precision medicine.
Gallium nitride (GaN) and its alloys with aluminum and indium (AlGaN, InGaN, InGaAlN) are technologically relevant semiconductors due to the direct and tunable energy gap, spanning from the near infrared to the ultraviolet. Moreover, their electrical, chemical, mechanical and thermal properties paved the way for applications in electronics, such as new generation high frequency / high power transistors, and optoelectronics, such as LEDs, lasers and photodetectors for UV. Our technology for nitrides is based on the metal organic chemical vapor deposition (MOCVD) technique combined with dedicated nanofabrication tools such as etching systems based on chlorine chemistry and UV lithography.
Research topics in CNR NANOTEC include:
- Electronics based on GaN technology: high electron mobility transistor;
- AlGaN photodetectors in metal-semiconductor-metal geometry for ultraviolet sensing in environmental and food applications;
- GaN /AlGaN biosensors.
Spintronic devices include different research fiels, from nanodevices based on magnetic molecules or particles, to magnetic multilayers, up to RF systems for hybrid spintronics. In addition, new materials are studied (e.g. multiferroic and functional oxides) and magnetic and ferroelectric characterizations are conducted (for further information http://www.omnics.it/home).
Energy harvesters exploit mechanical energy sources such as low-level vibrations caused by structural deformations, fluid flows or body movements with estimated power in the µW-mW range and represent promising building blocks of sustainable energy systems to be used for example in living systems and in the human body.
Wearable electro-optical devices have gained a considerable interest in recent years owing to their heir possible employment for monitoring of personal portable health and remote medical practices and the improvement of safety conditions in the workplace. Flexible OLEDs are integrated into flexible or textile based displays, as well as wearable optical sensors can track multiple vital signs such as heart rate, blood pressure and oxygen levels. Other applications for wearables include UV detection, measuring pollutant levels, explosive detection, both indoors and outdoors. The research activities are focused in the realization and characterization of several types of optoelectronic devices on substrates of different nature, such as fabric, and their combination with other components to realize smart systems. The scope includes applications of organic (carbon-based) semiconductors, hybrid systems incorporating both organic and inorganic materials, nanoparticle-based inks (e.g. colloidal 2D-TMDC, carbon nanotubes, graphene), processed by wet-techniques (printing and coating methods).
In order to effectively develop this new technology, we aim to focus on the tree following main sectors:
- to develop a new class of soluble materials for these applications;
- to develop new techniques for large area production;
- to develop electronic printed circuits.
Interactions of the above tree research area is the successful key for a mass production.
High quality factor microcavities (Q≈2000), based on DBR (Distributed Bragg Reflector), allow to study the light-matter interaction through the coherent exchange of energy between photons and excitons, also offering new opportunities for implementation of high performance optical circuits integrated in semiconductor chips. The research activities are carried out in collaboration with the CNR NANOTEC advanced Photonics & Optoelectronics research group.
Keywords: Electro-Optical Characterization, Organic and Inorganic Semiconductors
The advanced ELectrical and PHOtoelectrical characterization laboratory (ELPHO) contains state of the art facilities to study charge injection, transport mechanism and mobility properties of inorganic, organic and hybrid semiconductors, and more in general to investigate the electrical and photoelectrical properties of optoelectronic devices.
Charge injection, transport, trapping and mobility phenomena are fundamental to develop highly efficient optoelectronic devices, based on inorganic, organic or hybrid semiconductors. Hall-mobility measurements, Time of Flight (TOF), Charge Extraction by Linearly Increasing Voltage (CELIV), Space charge limited current (SCLC), Thermally Stimulated Current (TSC) techniques will be applied to study charge generation/injection, trapping, charge transport, and optical properties of different kind of materials.
We study a wide range of advanced materials ranging from inorganic (2D-TDMCs), hybrid (perovskites), organic (polymers, small molecules) semiconductors to conductive oxides (ITO, SnO2). Our main focus is on the realization from few layers (2D) up to bulk (3D) thin films using a wide range of depositions techniques from thermal evaporation, e-beam, R.F. Sputtering to solution cast and printed methods. Next, an extensive optical and electrical characterization is performed, followed by morphological and photophysical measurements that are of crucial importance to give a feedback to material scientists in order to optimize material properties and as consequence device efficiencies.