compoundsemiconductor.net: magazine

Dots speed datacom VCSELs

Mon, 29 Jun 2009 06:02:48 GMT

Transmitters operating well beyond 10 Gbit/s are needed for emerging communication standards. Quantum-dot VCSELs can operate at four times this, and even higher rates are promised with a design incorporating a modulator in the top mirror, says VI Systems' Nikolai Ledentsov.

SiC foundations assist AlN growth

Mon, 22 Jun 2009 06:02:39 GMT

Although AlN substrates have some great characteristics for UV-LED fabrication, it is very difficult to make this material. However, a fast sublimation growth process that deposits AlN onto SiC is producing very encouraging results, including incredibly low defect densities, say Mikael Syväjärvi, Reza Yazdi and Rositza Yakimova from Linköping University.

Research Review

Mon, 15 Jun 2009 06:03:01 GMT

Nitrogen radicals repair InN epilayers…HfO₂ dielectric layer increase output power…Native platform extends emitter life.

Epistar's chips plug and play

Mon, 15 Jun 2009 06:02:18 GMT

Conventional LEDs that are used for solid-state lighting have to be connected to an AC-to-DC converter. But this bulky power supply impacts efficiency and reliability, and can be discarded by turning to Epistar's AC-LEDs that feature on-chip rectification circuits, says Carson Hsieh.

Unsettled outlook hangs over CPV

Mon, 15 Jun 2009 06:02:09 GMT

Typically based on III-V solar cells, concentrated photovoltaics has the potential to be a fantastic source of renewable energy. But in a world where private finance has all but disappeared, Michael Hatcher wonders whether this fledgling industry has a future.

China's LED production begins to fulfill domestic demands

Mon, 15 Jun 2009 06:01:57 GMT

As recent as 2002, China imported all of its LED chips. It is now meeting half of this demand with domestic production and making the transition from incandescents to solid-state lighting. Richard Stevenson catches up with progress.

III-V industry stocks reach bottom?

Mon, 15 Jun 2009 06:01:47 GMT

The NASDAQ stock exchange has lost 40% of its value in the last 12 months, and the shares of most III-V players have fared worse. Well chosen acquisitions and manufacturing efficiency separate the winners and losers, finds Andy Extance.

Exploiting nature's secret stash

Mon, 08 Jun 2009 06:12:48 GMT

Phone-charging shoes? Wireless light switches? Photovoltaics that harness the warmth of radioactive isotopes? Energy harvesting is starting to gain momentum, finds Jon Cartwright.

LEDs get ready to take to the skies

Mon, 01 Jun 2009 06:12:39 GMT

Photonic quasicrystals and a droop-combating layer can create efficient LEDs with well-directed emission for navigational, taxi and landing lights in aircraft, and backlighting cockpit displays. Duncan Allsopp and Philip Shields describe the progress made under the UK's "Novelels" project.

Microsemi puts SiC on the radar

Tue, 26 May 2009 06:12:19 GMT

Radar's latest challenge is to uncover details of objects at vast distances. Vacuum tubes and silicon electronics are not up to the task, but Microsemi's SiC static induction transistors can aid this quest by delivering long, powerful pulses at a high duty cycle, says Mike Mallinger.