Site: University of Cambridge
Cavendish Laboratory
Toshiba Cambridge Research Center (TCRC)
Madingley Road
Cambridge CB3 0HE, United Kingdom
http://www.phy.cam.ac.uk/ (Cavendish Laboratory)

Date Visited: 15 October 1997

WTEC: J. Mendel (report author)

Hosts:

TOSHIBA CAMBRIDGE RESEARCH CENTER (TCRC)

Overview of the Center

The Toshiba Research Center (TCRC) was founded by the Toshiba Corporation of Japan as a laboratory pursuing fundamental research into the physics of semiconductor structures and associated topics. The intent is to provide an important part of electronics technology for the next century. This includes development of collaborative projects with academic institutions in the European community.

Accordingly, there is collaborative research with the Cavendish laboratory of Cambridge University on advanced growth and fabrication techniques. The Center maintains a close relationship with Toshiba Research and Development Center in Japan, and there are frequent reciprocal visits between the two centers.

Most research is for a 5- to 10-year horizon. Present staff totals about 18. All research is on semi-conductors, on which ~ 50 papers have been published since 1991, the year the center was established. The work includes papers on electrical properties of quantum well structures where the electron wave function is controlled by application of a voltage to a controlling gate leading to a velocity modulated transistor. The center has a full in-situ cleaning chamber, which is used prior to regrowth studies.

Studies of electron propagation on curved and nonplanar surfaces are also taking place, partly as a result of observing the improved electrical properties of advanced structures. Accordingly, the need to develop an optical facility became readily apparent. Surface orientation as a function of a magnetic field has led to the field taking on different values; electron deflection can take place as a result of the electron velocity in the magnetic field.

Extensive investigations into infrared properties as well as excitonic effects led to the discovery of the positively charged exciton. Included here were investigations on both positive and negative properties of excitons.

Funding Profile

Funding is by the Toshiba Corporation.

Research and Development Highlights

Concluding Remarks

The Toshiba Center is ideally positioned to explore electrical and quantum phenomena for semiconductor technology for the next century, due to its location, expertise of technical resources, and close association with collaborative communities such as Cavendish. Its path forward appears rewarding and certain.

CAVENDISH LABORATORY

Dr. Neil Greenham, associated with Prof. Richard Friend in the Conjugated Polymers and Molecular Solids Group, was the principal contact for this visit.

Overview of the Laboratory

Experimental and theoretical research in the Department of Physics at Cambridge is carried out in the Cavendish Laboratory. The laboratory was established 120 years ago by individuals such as Maxwell, Rayleigh, Thomson, Rutherford, and Bragg. From this noteworthy beginning the laboratory has evolved into three major sections: Condensed Matter Physics, Radio Astronomy, and High Energy Physics.

The funding for the investigations at the laboratory come from a combination of government and industry. There are currently some 63 companies that sponsor research at Cavendish.

Research and Development Highlights

The following areas of research are active in the area of optical and electrical studies:

Discussion

Conjugated polymers with delocalized electron systems behave as model organic semiconductors. Here activities such as design and synthesis of new polymers are of interest for the semiconductor physics of these materials. They give strong electro-optical and nonlinear optical responses. There is concern for polymer light-emitting diodes as well as photovoltaic and photoconductor diodes. Subpicosecond time-resolved spectroscopy is included also. There is considerable collaboration with the Chemistry Department in order to tailor these materials to the appropriate properties needed for these studies.

Equipment at Cavendish

  • X-ray diffractometer
  • Atom scattering facilities
  • Low energy electron diffraction
  • Electron microscopy
  • High resolution electron energy loss measurements
  • Angle-resolved photoemission
  • Scanning tunneling microscope
  • Tunable dye lasers
  • Optical spectrometers
  • Laser Raman
  • Fourier infrared spectroscopy
  • Molecular beam epitaxy
  • Ion beam & electron beam lithography
  • HITACHI CAMBRIDGE LABORATORY

    Although this site was not visited, it is included in the report for the reader's interest (see also http://www-hcl.phy.cam.ac.uk/).

    Key Personnel: Prof. H. Ahmed, Microelectronics Research Center

    Staff: Six Post Doctorates, 17 Research Students

    Overview of the Laboratory

    The purpose of this laboratory is to carry out research into physics and fabrication of novel electronic devices. Activities include:

    Discussion

    The Microelectronics Research Center has regular collaboration on quantum effect devices with the Cambridge Physics Laboratory. There is extensive equipment sharing. For example: a femtosecond laser system, an ultra-low temperature scanning tunneling microscope and a powerful system are shared for purposes of characterization on structures that are fabricated in the Center.

    Also, a newly organized group within the Center is investigating sensor structures including an infrared sensor based on free-standing micro-thermocouples. Work is in process on microsensors in silicon and GaAs and on single-molecule sensors.


    Published: September 1999; WTEC Hyper-Librarian