Science Daily May 11, 2022 An international team of researchers (Italy, Spain, USA – MIT) has developed the quasi-particle counterpart, a superconducting tunnel diode with zero conductance in only one direction. The direction-selective propagation of the charge was obtained through the broken electron-hole symmetry induced by the spin selection of the ferromagnetic tunnel barrier: a EuS thin film separating a superconducting Al and a normal metal Cu layer. The Cu/EuS/Al tunnel junction achieved a large rectification (up to ∼40%) already for a small voltage bias (∼200 μV) due to the small energy scale of the system. With the help of an […]
Tag Archives: Diodes.
Tailored meta-grid of nanoparticles boosting performance of light-emitting diodes
Phys.org July 29, 2020 Current methods to use new materials for increasing LED light output are has led to the LED chips becoming bulkier or costly to manufacture. According to a theoretical model proposed by researchers in the UK a significant enhancement in light extraction from LEDs can be achieved by boosting the transmission across LED-chip/encapsulant interface. They propose introducing a monolayer of plasmonic nanoparticles on top of the LED chip which can reduce the Fresnel reflection loss at the chip/encapsulant interface. A similar effect is also applicable for enhancing the trapping of light in solar cells…read more. Open Access […]
A perovskite-based diode capable of both light emission and detection
Phys.org April 10, 2020 An international team of researchers (Sweden, China, Italy, Switzerland) has developed an efficient solution-processed perovskite diode that can work in both emission and detection modes. The device can be switched between modes by changing the bias direction, and it exhibits light emission with an external quantum efficiency of over 21% and a light detection limit on a subpicowatt scale. The operation speed for both functions can reach tens of megahertz. The diodes exhibit a high specific detectivity at its peak emission (~804 nm), which allows an optical signal exchange between two identical diodes. To illustrate the potential […]
Developing technologies that run on light
Eurekalert July 24, 2019 Researchers at Stanford University designed arrays of ultra-thin silicon disks that work in pairs to trap the light and enhance its spiraling motion until it finds its way out. This results in high transmission in the forward direction. When illuminated in the backwards direction, the acoustic vibrations spin in the opposite direction and help cancel out any light trying to exit. Theoretically, there is no limit to how small this system could be. According to the researchers efficient photonic diodes is paramount to enabling next-generation computing, communication and even energy conversion technologies. The increased speed and […]