book of abstracts - IM2NP

A B S T R A C T S THURSDAY, JULY 1 N A N O S E A 2 0 1 0
10H20-10H40
Temperature dependent photoluminescence properties of InAs/InP quantum
sticks subjected to low energy phosphorous ion implantation and subsequent
annealing.
M. H. Hadj Alouane, B. Ilahi* and H. Maaref, B. Salem#, V. Aimez, and D. Morris,
A. Turala, P. Regreny, and M. Gendry ((1) Laboratoire de Micro-Optoélectronique et Nanostructures,
Faculté des Sciences, Avenue de l‟environnement, 5019 Monastir, Tunisia. (2)Centre de Recherche en
Nanofabrication et Nanocaractérisation (CRN2), Université de Sherbrooke, (Québec) Canada J1K 2R1. (3) Institut
des Nanotechnologies de Lyon, UMR 5270, Bat. F7, 36 avenues Guy de Collongue, 69134 Ecully Cedex, France).
bouraoui.ilahi@fsm.rnu.tn
1 – Introduction
For monolithic integration of QD-based optoelectronic devices, selective post growth energy band gap
tuning of QD structures is highly required. It can be ensured by spatial selective intermixing across the same
sample surface. Among the existing intermixing techniques, low energy-ion-implantation and subsequent
annealing is the most suitable process allowing: reproducibility, area selectivity and precise control of the
defects depth and concentration. Extensive reports already exist on the effect of intermixing on the low
temperature luminescence peak position, linewidth and integrated intensity. However, there are still some
unknowns concerning the evolution of the temperature dependent photoluminescence properties as a
function of the intermixing degree. The investigation and understanding of this phenomenon is important to
assure efficient control of the device performance.
2 – Abstract
In this work, the temperature dependent photoluminescence (PL) spectra was performed on InAs/InP
quantum sticks QSs samples which were implanted with phosphorus ions at doses in the range of 1x 1011 –
5x 1014cm-2 and subsequently annealed at 600°C for 120s to set off the intermixing. More details
concerning the growth and implantation procedure can be found elswhere1.
10 K PL measurements revealed a purely induced phosphorus-ion-implantation blue-shift as large as 275
meV for an implantation dose of 5x1013 cm-2. Higher implantation doses results in saturation of the
blueshift and a decrease of the integrated PL intensity. The FWHM is found to increase with increasing the
ion implantation dose up 1012 cm-2. Higher implantation doses result in a narrowing of the PL linewidth.
The broadening of the PL linewidth at lower doses can be explained by an inhomogeneous intermixing
process which occurs when the density of vacancies is below the onset required for efficient QS
intermixing2.
No major modifications were observed in the temperature behavior of luminescence peak for the as-grown,
only annealed sample and sample implanted at 1011 cm-2. For ion implantation doses in the intermediate
range (1012 to 1013 cm-2), the emission energies exhibits a kink effect with a V shaped PL linewidth. As a
consequence of the inhomogeneous intermixing enhanced QS‟s size and composition dispersion, for the
latter dose‟s range, the temperature dependent PL is found to be dominated by carriers transfer between
intermixed and non intermixed QSs having different confining potential depth.
For higher implantation doses, QSs are uniformly intermixed which reduces carrier transfer. Accordingly, for
implantation doses above 5x1013 cm-2, we have observed, a continuous increase of the PL linewidth with
increasing temperature. Such a behavior has also been observed for the non-intermixed QSs samples and
correlated with the electron-phonon scattering. However, the PL emission energies are found to deviate from
Varshni empirical law at lower temperature. The observed behavior can be interpreted in terms of carriers
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