The ideal optoelectronic semiconductor material should be a strong light emitter i.e. should emit light very efficiently upon optical excitation as well as be an efficient charge conductor to allow for electrical injection in devices. These two conditions when met can lead to highly efficient light emitting diodes as well as to solar cells with […]
Nano-Imaging Of Intersubband Transitions In Few-Layer 2-D Materials
Semiconducting heterostructures have been key to the development of electronics and opto-electronics. Many applications in the infrared and terahertz frequency range exploit transitions, called intersubband transitions, between quantized states in semiconductor quantum wells. These intraband transitions exhibit very large oscillator strengths, close to unity. Their discovery in III-V semiconductor heterostructures depicted a huge impact within […]
The Photoexcited Graphene Puzzle Solved
Light detection and control lies at the heart of many modern device applications, such as the camera you have in your phone. Using graphene as a light-sensitive material for light detectors can offer significant improvements with respect to materials being used nowadays. For example, graphene can detect light of almost any colour, and it gives […]
Graphene And Quantum Dots Put In Motion A CMOS-Integrated Camera That Can See The Invisible
Over the past 40 years, microelectronics have advanced by leaps and bounds thanks to silicon and CMOS (Complementary metal-oxide semiconductors) technology, making possible computing, smartphones, compact and low-cost digital cameras, as well as most of the electronic gadgets we rely on today. However, the diversification of this platform into applications other than microcircuits and visible […]
Energy Decay in Graphene Resonators
Energy dissipation is a key ingredient in understanding many physical phenomena in thermodynamics, photonics, chemical reactions, nuclear fission, photon emissions, or even electronic circuits, among others. In a vibrating system, the energy dissipation is quantified by the quality factor. If the quality factor of the resonator is high, the mechanical energy will dissipate at a […]
Solar Cells for Greener, Safer Energies
Nowadays, our world is in search of cleaner energy sources to power our increasing industrial and economical needs. Solar energy is becoming an alternative source to fossil fuels, however, due to the accelerating pace at which we are consuming energy, we need to develop ubiquitous PV technologies that can be employed everywhere: on buildings, clothes, […]
Graphene Enables All-Electrical Control of Energy Flow from Light Emitters
At the heart of lasers, displays and other light-emitting devices lies the emission of photons. Electrically controlled modulation of this emission is of great importance in applications such as optical communication, sensors and displays. Moreover, electrical control of the light emission pathways opens up the possibility of novel types of nano-photonics devices, based on active […]