My journal highlighted in SciTech

Salam,

Taken from SciTech Asia Pacific website. They highlighted my recently published journal.

Url: http://www.scitechpap.com/?p=661

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Monday 25 April 2011

Semiconducting bismuth alloys (MAS, UK)

Malaysian and UK collaboration yields high quality GaAsBi alloys by molecular beam epitaxy for optoelectronic applications.

A precise and reproducible method for controlling the band gap of semiconductors is invaluable for the development of optoelectronic devices. Recent reports show that the addition of bismuth (Bi)—a semimetal—to thin films of gallium arsenide (GaAs) reduces the band gap by 88 meV per percent of Bi. This large reduction in the band gap is promising for the fabrication of long wavelength optical devices.

However, in spite of the tremendous potential of Bi-semiconducting alloys, Bi segregates and forms droplets on GaAs substrates during film deposition.

Here, Abdul Rahman Mohmad at the National University of Malaysia in collaboration with researchers in the United Kingdom describe the photoluminescence (PL) properties of high quality GaAsBi (Bi=3%) thin films grown on GaAs substrates by molecular beam epitaxy.

Notably, the researchers observed a room temperature PL peak at 1038 nm with a full width half maximum of 75 meV, which is significantly narrower than other reports and indicates low alloy fluctuations in the film.

The researchers ascribe the improvement in the film quality to the higher temperature of 400^oC used growth—compared with the typical 270–380^oC.

The ability to produce high quality GaAsBi alloys offers new opportunities for the fabruication optoelectronic devices, including spintronic structures exploiting the the large spin-orbit bowing of GaAsBi alloys.

Further information
Publications and Affiliations
A. R. Mohmad,^1,2 F. Bastiman,¹ J. S. Ng,¹ S. J. Sweeney,³ and J. P. R. David¹, Photoluminescence investigation of high quality GaAs_1−xBi_x on GaAs. Applied Physics Letters, 98, 122107, (2011).

1. Department of Electronic and Electrical Engineering, University of Sheffield, Sir Frederick Mappin Building, Mappin Street, Sheffield S1 3JD, United Kingdom
2. Institute of Microengineering and Nanoelectronics, National University of Malaysia, Bangi, 43000 Selangor, Malaysia
3. Advanced Technology Institute and Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH, United Kingdom