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University of California, Berkeley  
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Nanowires
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III-V Nanoneedles - surprising structures enable lasers and photonics on CMOS-Si

Students: Roger Chen, Wai Son Ko, Kun Li, Fanglu Lu, Kar Wei Ng, Fan Ren, Thai-Truong D. Tran

Silicon is the basis for electronic devices, and III-V semiconductors make the best photonic components, but the crystal lattice mismatch between these material types has made integrating the two a longstanding research problem. Our group has discovered a new GaAs-based nanostructure that overcomes this roadblock: sharp, hexagonal pyramids of high-quality crystal that grow catalyst-free at CMOS-compatible temperatures directly on silicon, sapphire, and other substrates. The nanoneedles scale with growth time and can be layered, doped, as well as selectively etched to create robust on-chip structures for diverse applications, including optical interconnects, microscopy, field emission, nonlinear optical signal generation, sensors, displays, and nanofluidics. In our group, we are developing novel nano-optoelectronic devices based on nanoneedles. Our research includes growth by metal-organic chemical vapor deposition (MOCVD), material and optical characterization, as well as device fabrication and testing.

Nanoneedle TEM and SEM

Growth, crystallography, and optical studies have shown nanoneedles to have a unique, single crystal dislocation-free wurtzite lattice, which can be used for lasing and second harmonic generation. The high crystal quality of III-V nanoneedles grown on silicon is unmatched, making nanoneedles an exciting approach towards developing practical silicon-based optoelectronics for the future.

Nanoneedle Optical Properties

Using standard microfabrication techniques, we have thus far demonstrated two nanoneedle-based devices directly grown on silicon wafers: GaAs avalanche photodiodes (APDs) and InGaAs/GaAs light emitting diodes (LEDs). Testing at room temperature reveals that nanoneedle-based APDs are more sensitive, pack more densely, and demand less power than existing designs. Room temperature electroluminescence from nanoneedle LEDs meanwhile demonstrates a critical first step towards an electrically-pumped laser.

Nanoneedle Growth Mode


Selected Publications:

  1. Roger Chen, Thai-Trung D. Tran, Kar Wei Ng, Wai Son Ko, Linus C. Chuang, Forrest G. Sedgwick, Connie Chang-Hasnain, “Nanolasers grown on silicon,” Nature Photonics 5, 170-175 (2011).
  2. Linus C. Chuang, Forrest G. Sedgwick, Roger Chen, Wai Son Ko, Michael Moewe, Kar Wei Ng, Thai-Truong D. Tran, Connie Chang-Hasnain, “GaAs-Based Nanoneedle Light Emitting Diode and Avalanche Photodiode Monolithically Integrated on a Silicon Substrate,” Nano Letters 11, 385-390 (2011).
  3. Linus C. Chuang, Roger Chen, Forrest Sedgwick, Wai Son Ko, Kar Wei Ng, Thai-Truong D. Tran, Connie Chang-Hasnain, “InGaAs QW Nanopillar Light Emitting Diodes Monolithically Grown on a Si Substrate,” Conference on Lasers and Electro-Optics, May 2010.
  4. Shanna Crankshaw, Linus C. Chuang, Michael Moewe, Connie Chang-Hasnain, “Polarized zone-center phonon modes of wurtzite GaAs,” Phys. Rev. B 81, 233303 (2010).
  5. Roger Chen, Shanna Crankshaw, Thai-Truong D. Tran, Linus C. Chuang, Michael Moewe, Connie Chang-Hasnain, “Second-harmonic generation from a single wurtzite GaAs nanoneedle,” Appl. Phys. Lett. 96, 051110 (2010).
  6. Michael Moewe, Linus C. Chuang, Shanna Crankshaw, Kar Wei Ng, Connie Chang-Hasnain, “Core-shell InGaAs/GaAs quantum well nanoneedles grown on silicon with silicon-transparent emission,” Opt. Express 17, 7831-7836 (2009).
  7. Linus C. Chuang, Forrest Sedgwick, Wai Son Ko, Michael Moewe, Connie Chang-Hasnain, “GaAs-Nanoneedle Avalanche Photodetectors Monolithically Grown on a Si Substrate,” International Symposium on Compound Semiconductors, September 2009.
  8. Michael Moewe, Linus C. Chuang, Shanna Crankshaw, Chris Chase, Connie Chang-Hasnain, “Atomically sharp catalyst-free wurtzite GaAs/AlGaAs nanoneedles grown on silicon,” Appl. Phys. Lett. 93, 023116 (2008).


Last Updated December 2010