Investigation of structural and optical properties of Ag nanoclusters formed in Si(100) after multiple implantations of low energies Ag ions and post-thermal annealing at a temperature below the Ag-Si eutectic point

Abstract

Articles you may be interested inResistive switching characteristics in dielectric/ferroelectric composite devices improved by post-thermal annealing at relatively low temperature Appl. Phys. Lett. 104, 092903 (2014) were sequentially implanted into Si(100) to create a distribution of different sizes and densities of buried metal nanoclusters (NC) at the near-surface layers. These structures have applications in fields involving plasmonics, optical emitters, photovoltaic, and nano-electronics. The dimension, location and concentration of these NCs influence the type of the applications. The implantation profiles were simulated by utilizing the widely used Stopping and Range of Ions in Matter (SRIM) code as well as a dynamic-TRIM code, which accounts for surface sputtering. The implanted samples were subsequently annealed either in a gas mixture of 4% H 2 + 96% Ar or in vacuum at a temperature ~500 ºC up to 90 minutes. The annealing was carried out below the eutectic temperature (~ 841 ºC) of Ag-Si to preferentially synthesize Ag NCs in Si rather than silicide. In order to study the size, concentration and distribution of the Ag NCs in Si, the samples were characterized by Rutherford Backscattering Spectrometry (RBS), X-ray photoelectron spectroscopy (XPS) in combination with Ar-ion etching, and Transmission Electron Microscopy (TEM) techniques. The annealed samples showed a preferential distribution of the Ag NCs' sizes up to 10 nm either near the surface region (< 25nm) or at deeper layers (60-80 nm) closer to the interface of the implanted layer with the crystalline Si substrate. Ag NCs of larger diameters (up to 15 nm) were seen in the annealed sample near the peak concentration positions (~35-55 nm) of the implanted Ag ions. We have investigated the optical absorption properties due to these nano-structures in Si. The multiple energy implanted samples annealed in a gas mixture of 4% H 2 + 96% Ar show enhancements in the optical absorption in the visible range.

Improvement in the photocurrent collection due to enhanced absorption of light by synthesizing staggered layers of silver nanoclusters in silicon

“…The absorption in the region labeled (c) observed in all the absorption spectra ( Fig. 6 (A) and (B)), which is due to the defect mitigated absorption, and may not be from the quantum confinement of the NCs [17,24]. This characteristic peak is observed by many other groups [24].…”

“…In a previous article we have discussed in details the structural characterization of the Ag implanted samples and distribution of the Ag NCs inside the ion implanted region [17]. A cross-sectional TEM image of a representative sample is shown in figure 4.…”

“…In order to investigate the role of defects on the optical properties, some of the Si samples were implanted with 60 keV Si at fluences ranges from 1×10 14 to ~1×10 15 atoms/cm 2 and 40 keV deuterium with a fluence of 1×10 14 atoms/cm 2 . The Ag ion implanted Si samples were prepared as multiple implants at different ion energy and fluence conditions as described previously [17]. Samples were subsequently annealed under different conditions to enhance light absorption.…”

“…In this study, we have investigated the optical absorption from staggered layers of Ag NCs synthesized in Si (100) substrate by sequentially implanting multiple energies (< 80 keV) and different fluences (ranging from ~1×10 16 to ~1×10 17 atoms/cm 2 ) of Ag ions and subsequent thermal annealing [17]. The details of the fabrication technique for the Ag staggered layer is reported elsewhere [17]. Here, we report the investigations into the photocurrent collection in samples with these staggered Ag NC-Si layers.…”

Формирование композиционного материала на основе GeSi с наночастицами Ag методом ионной имплантации

“…При этом атомная концентрация в максимуме составляет 14 at.% для ионов Ag + и 18 at.% для ионов Ge + . Такое поведение изменений профилей распределения примеси по глубине образца при учете эффекта распыления поверхности оказывается сходным с ранее проведенными расчетами различных импланти-рованных материалов [25,26]. Толщина имплантирован-ного слоя Si для обоих ионов Ge + и Ag + составляет около 50 nm, что коррелирует с величиной, полученной экспериментально методом эллипсометрии для подобно-го образца Ag : Si [27].…”