LED could signal silicon laser
A new LED could lead to a silicon-compatible light source
First light on silicon laser
The internal energy levels of bulk silicon – in particular its ‘indirect bandgap’ – makes it emit light very inefficiently. Existing lasers are therefore based on ‘direct...
Descartes prize applauds European cooperation
Dago de Leeuw, a physicist at Philips Research Laboratories in the Netherlands, leads a team of physicists recognized for their pioneering research in plastic electronics. De Leeuw and colleagues from...
The great atom race
Atoms move through the crystal lattice of a solid by a process called diffusion. The atoms migrate by swapping places with ‘point defects’ such as vacancies – empty spaces in the lat...
Nobel prize goes to semiconductor pioneers
Kroemer and Alferov share the prize for their work on semiconductor heterostructures – devices that contain thin layers of different semiconductors, usually based on gallium arsenide, stacked on...
Defects boost optical communications
In a photonic crystal the periodic variation of the dielectric constant results in a range of ‘forbidden’ frequencies called a photonic bandgap (PBG). Electromagnetic waves with a ‘f...
Superconducting gains
The device has three electrodes: a niobium injector electrode; a common electrode that consists of a layer of niobium and a layer of aluminium; and a niobium detector electrode. The electrodes are sep...
Looking inside quantum dots
Manfred Bayer of the University of Wurzburg in Germany, and co-workers in Wurzburg and the National Research Council of Canada in Ottawa, studied indium gallium arsenide quantum dots grown on a galliu...
New light on organic LEDs
Light emission from organic materials occurs through two separate processes: fluorescence – the process by which today’s organic semiconductors produce light – and phosphorescence. I...
Conductivity measurements made on a single strand of DNA
The Delft group fabricated the electrodes by making a slit in a silicon nitride film with standard lithography. A series of platinum layers were then sputtered across the slit until the gap was reduce...
