Near-IR multi-quantum-well SiGe detectors show promise for photonics integration

High-quality single-crystal silicon-germanium (SiGe) multi-quantum-well layers were epitaxially grown on silicon substrates by researchers at Bilkent University (Ankara, Turkey), the Massachusetts Institute of Technology (Cambridge, MA), Korea University (Seoul, South Korea), and the Masdar Institute of Science and Technology (Abu Dhabi, UAE). The layers were fashioned into mesa-structured p-i-n photodetectors functioning at telecommunications wavelengths with reverse leakage currents of about 10 mA/cm2 and responsivities above 0.1 A/W in the 1300 to 1600 nm range. The spectral response of the photodetectors was voltage-tunable via altering the reverse bias, shifting the absorption edge by tens of nanometers.

The creation of GeSi devices on silicon is important for large-scale optical and optoelectronic circuits, as SiGe fabrication is compatible with complementary metal-oxide semiconductor (CMOS) technologies used to fabricate silicon computer chips. The ten quantum wells for the p-i-n detectors consisted of 10-nm-thick germanium wells and 20-nm-thick Si0.1Ge0.9 barriers, with the strained germanium lattice contributing to a high light absorption. Photodiodes were made with mesa diameters ranging between 20 and 120 μm; for devices with mesa areas less than 100 μm2, the RC time constant was estimated to be below one picosecond. Contact Ali Okyay at aokyay@ee.bilkent.edu.tr.



Most Popular Articles

50 YEARS OF GAS LASERS


Durable survivors evolve new forms

Webcasts

Laser Measurements Critical to Successful Additive Manufacturing Processes

Maximizing the stability of the variables going into any manufacturing process is what ensures ts consistency and high quality. Specifically, when a laser is...

Ray Optics Simulations with COMSOL Multiphysics

The Ray Optics Module can be used to simulate electromagnetic wave propagation when the wavelength is much smaller than the smallest geometric entity in the ...

Multichannel Spectroscopy: Technology and Applications

This webcast, sponsored by Hamamatsu, highlights some of the photonic technology used in spectroscopy, and the resulting applications.

Handheld Spectrometers

Spectroscopy is a powerful and versatile tool that traditionally often required a large and bulky instrument. The combination of compact optics and modern pa...
White Papers

All About Aspheric Lenses

The most notable benefit of aspheric lenses is their ability to correct for spherical aberration....

Wavelength stabilized multi-kW diode laser systems

Wavelength stabilization of high-power diode laser systems is an important means to increase the ...

Narrow-line fiber-coupled modules for DPAL pumping

A new series of fiber coupled diode laser modules optimized for DPAL pumping is presented, featur...
Technical Digests

ADHESIVES, SEALANTS, AND COATINGS: Solutions for optical technologies

A vast array of optical systems of various types and degrees of complexity require the use of adh...

WAVELENGTH-SWEPT LASERS: Dispersion-tuned fiber laser sweeps over a 140 nm range for OCT

By eliminating the use of mechanical tunable filters and instead tuning by intensity-modulation i...

Keeping pace with developments in photonic materials research

For demanding or custom spectroscopy solutions, care must be taken in selecting and integrating a...

HIGH-POWER FIBER LASERS: Working in the kilowatt regime

High-power materials-processing fiber lasers are available in an increasing variety of forms, as ...

Click here to have your products listed in the Laser Focus World Buyers Guide.
Social Activity
  •  
  •  
  •  
  •  
  •  
Copyright © 2007-2014. PennWell Corporation, Tulsa, OK. All Rights Reserved.PRIVACY POLICY | TERMS AND CONDITIONS