Samples of lnAs and lnSb either singly or doubly doped with Si and Be impurities have been studied using FTIR absorption spectroscopy and Raman scattering. Localized vibrational modes of ''Si,, donors and *Be,, acceptors have been identified at 359 and 435cm-' respectively in InAs. The two impurities give corresponding lines at 316 and 414"' in InSb. Comparisons are made with the behaviour of the same impurities in compensated or p-type GaAs. Strong resonance effects relating to the incident photon energy are found in t h e Raman spectra of donors.

In order to strengthen the position of CNT actuator technology and fasten the transfer of scientific results into application development and market introduction scientific institutes AIST Kansai and Fraunhofer IPA cooperated in the field of electroactive polymers.Automated dosing of small amounts of liquids normally involves quite large pipettes and motors for pipette actuation. Miniaturized pipettes can enable new areas, in which micro dosing is demanded and could be particularly beneficial in the field of medical or (bio-) chemical applications.The approach was the direct integration of a bending CNT actuator into a PCB design, which enables a frictionless induction of movement onto a liquid. The driving electronics control the actuator with a low voltage and can be placed on the same PCB.The result is a smooth, tailorable dispensation of liquid from the pipette with the ability to integrate the pipette into a fully automated system.

We have used secondary ion mass spectrometry, local vibrational mode infrared absorption, and electrical characterization to study the incorporation of Si delta-doped planes in GaAs grown by molecular beam epitaxy at 400 "C, in the concentration range 0.01-0.5 monolayers. A correspondence is observed between the density of Sio donors, the free electron concentration and the total Si coverage, up to a coverage of -lOi3 cmm2; -however, above this value, the electron density falls, while [Sio,] remains constant up to a coverage of -lOI cm-', and then falls below the detection-limit at 0.5 monolayer coverage. These effects have been interpreted in terms of a model which takes account of Si migration and aggregation on the delta-doped plane during deposition. 633

Samples of p-type Ga-rich non-stoichiometric undoped liquidencapsulated Czochralski GaAs have been subjected to 2 MeV electron irradiation, carried out in stages, to cause the Fermi level to move upwards from the valence band. At each stage, infrared absorption measurements were made of the strengths of electronic transitions from levels at 78 meV and 203 meV a n d vibrational absorption at 601 cm-' from "EAa. The results are consistent with an assignment of the three signatures to "E:, , E, . and E: ; , in agreement with our previous proposals but in disagreement with other recently published results. The commonly held view that t h e 78/203 meV defect is due to Ga,. antisites cannot therefore be considered to be established.

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