HBZ Team Creates Novel Light-emitting Nano-architecture


Growing nanocrystals of GaAs on tiny columns of silicon and germanium could lead to new types of sensors, LEDs, and solar cells

A team at the HZB (Helmoltz Zentrum Berlin) has succeeded in growing nanocrystals of GaAs on tiny columns of silicon and germanium. This enables extremely efficient optoelectronic components for important frequency ranges to be realised on silicon chips.

GaAs semiconductors have better optoelectronic properties compared to silicon. And those properties can be controlled by specific nanostructures. Sebastian Schmitt, Silke Christiansen and their collaborators have succeeded in building such a nanostructure on a silicon wafer covered with a thin, crystalline layer of germanium.

Colleagues from Australia produced the high-quality wafer and sent it to HZB. The thin film of germanium facilitates the growth of GaAs crystals because the lattice constants of germanium and GaAs are almost identical.

They etched deep trenches in these wafers at intervals of a few micrometers until only a series of fine silicon columns topped with germanium remained on the substrate. GaAs was then deposited using MOVPE.

In this way, both gallium and arsenic atoms were systematically deposited on each germanium-capped silicon tower, forming a tiny, almost-perfect crystal. “The germanium acts like a crystallisation nucleus", explains Schmitt who is the author of the study published in Advanced Optical Materials.

"The nano-architecture looks spectacular under the electron microscope. At first glance, it seems as if you can see a cube on the tip of each silicon needle. At second glance, it becomes apparent that it is actually a rhombic dodecahedron – with each of the twelve surfaces an identical rhombus."

This nano-structure exhibits unusually high optical emission after excitation with a laser, especially in the near-infrared region.

“As the GaAs crystals grow, germanium atoms also become incorporated into the crystal lattice", explains Schmitt.

This incorporation of germanium leads to additional discrete energy levels for charge carriers that emit light when falling back to their original levels. The light is then amplified by means of optical resonances in the highly symmetrical nanocrystal, and the frequency of these resonances can be controlled by size and geometry of the crystals. A large number of these so-called photonic resonances could be detected in the experiment that also agree well with numerical calculations.

“Because the optical and electronic properties of semiconductors can be strongly modified by nanostructuring, such nano-architectures are well suited for developing novel sensors, light-emitting diodes, and solar cells", says Schmitt.

'Germanium template assisted integration of GaAs nanocrystals on silicon: a versatile platform for modern optoelectronic material', by S. W. Schmitt et al; Advanced Optical Materials (2018)

Helium Leak Detector Solutions
Siltectra Ramps Up Wafering Services
Himax Technologies Rebukes Motley Fool Article
Infineon Expands U.S.-based IoT Security Research And Development Programs
Future Of Quantum Technology In UK Given Significant Funding Boost
Mirsense And XenomatiX Win Technology Showcase At European MEMS, Imaging And Sensors Event
Picosun Launches New Solutions Specially Targeted For Healthcare Industries
RIT Awarded $422K Grant For PIC Technology
Thermco Systems Expands Global Operations With Acquisition Of CSD Epitaxy
Pfeiffer Vacuum Opens New High-tech Production Site In Romania
Teledyne E2v’s Emerald 12M And 16M Image Sensors Enter Mass Production
NanoScientific Symposium On Scanning Probe Microscopy (SPM)
ON Semiconductor To Demonstrate Innovation In Automotive, Power Conversion And IoT At Electronica
AES Announces Acquisition Of Advanced Research Manufacturing (ARM)
VTT Is Ranked Fourth In The World's Largest Research Funding Programme
Brixon Licenses Sensor Technology From ORNL
Imec.xpand Raises EUR 117 Million To Invest In Innovative, Early-stage Ideas
Intel Respond In Court To Qualcomm’s Claims
Webinar: On-Site Hydrogen Production Improves Safety, Quality, And Productivity In Wafer, Chip And Semiconductor Manufacturing
Palomar Technologies Awarded ISO 9001:2015 Certificate
ESI’s New Allegro LC Extends High-Volume Test Capability To Larger MLCCs
Biosensor Allows Real-Time Oxygen Monitoring For ‘Organs-On-A-Chip’
Cadence Recognized With Four 2018 TSMC Partner Of The Year Awards
Shin-Etsu Silicones Of America Primed For Growth

Search the news archive

To close this popup you can press escape or click the close icon.
Register - Step 1

You may choose to subscribe to the Silicon Semiconductor Magazine, the Silicon Semiconductor Newsletter, or both. You may also request additional information if required, before submitting your application.

Please subscribe me to:


You chose the industry type of "Other"

Please enter the industry that you work in:
Please enter the industry that you work in: