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Dominic Duffy

Postgraduate research student
MPhys (Hons)
+44 (0)1483 682741
08 ATI 02

My publications


Sharpe M. K., Marko I. P., Duffy D. A., England J., Schneider E., Kesaria M., Fedorov V., Clarke E., Tan C. H., Sweeney S. J. (2019) A comparative study of epitaxial InGaAsBi/InP structures using Rutherford backscattering spectrometry, X-ray diffraction and photoluminescence techniques,JOURNAL OF APPLIED PHYSICS 126 (12) 125706 AMER INST PHYSICS
In this work, we used a combination of photoluminescence (PL), high resolution X-ray diffraction (XRD), and Rutherford backscattering
spectrometry (RBS) techniques to investigate material quality and structural properties of MBE-grown InGaAsBi samples (with and without
an InGaAs cap layer) with targeted bismuth composition in the 3%?4% range. XRD data showed that the InGaAsBi layers are more homogeneous in the uncapped samples. For the capped samples, the growth of the InGaAs capped layer at higher temperature affects the quality of the InGaAsBi layer and bismuth distribution in the growth direction. Low-temperature PL exhibited multiple emission peaks; the peak
energies, widths, and relative intensities were used for comparative analysis of the data in line with the XRD and RBS results. RBS data at a
random orientation together with channeled measurements allowed both an estimation of the bismuth composition and analysis of the
structural properties. The RBS channeling showed evidence of higher strain due to possible antisite defects in the capped samples grown at
a higher temperature. It is also suggested that the growth of the capped layer at high temperature causes deterioration of the bismuth-layer
quality. The RBS analysis demonstrated evidence of a reduction of homogeneity of uncapped InGaAsBi layers with increasing bismuth concentration. The uncapped higher bismuth concentration sample showed less defined channeling dips suggesting poorer crystal quality and
clustering of bismuth on the sample surface.