Characterization of InSb Nanoparticles Synthesized Using Inert Gas Condensation

Sneha G Pandya,Martin E Kordesch

doi:10.1186/s11671-015-0966-4

Abstract

Nanoparticles (NPs) of indium antimonide (InSb) were synthesized using a vapor phase synthesis technique known as inert gas condensation (IGC). NPs were directly deposited, at room temperature and under high vacuum, on glass cover slides, TEM grids and (111) p-type silicon wafers. TEM studies showed a bimodal distribution in the size of the NPs with average particle size of 13.70 nm and 33.20 nm. The Raman spectra of InSb NPs exhibited a peak centered at 184.27 cm−1, which corresponds to the longitudinal optical (LO) modes of phonon vibration in InSb. A 1:1 In-to-Sb composition ratio was confirmed by energy dispersive X-ray (EDX). X-ray diffractometer (XRD) and high-resolution transmission electron microscopy (HRTEM) studies revealed polycrystalline behavior of these NPs with lattice spacing around 0.37 and 0.23 nm corresponding to the growth directions of (111) and (220), respectively. The average crystallite size of the NPs obtained using XRD peak broadening results and the Debye-Scherrer formula was 25.62 nm, and the value of strain in NPs was found to be 0.0015. NP’s band gap obtained using spectroscopy and Fourier transform infrared (FTIR) spectroscopy was around 0.43–0.52 eV at 300 K, which is a blue shift of 0.26–0.35 eV. The effects of increased particle density resulting into aggregation of NPs are also discussed in this paper.

Highlights

Indium antimonide (InSb) is a well-known III-IV semiconductor with one of the smallest band gaps (~0.17 eV at 300 K) and the highest room-temperature electron mobility (~78,000 cm2/(Vs)[2])
Coalescence is a process in which the sputtered entities sinter and diffuse within the particles when entities come in contact, and coagulation refers to the process where two or more nuclei are join by processes such a Brownian motion
To summarize, we have demonstrated a vapor phase technique to synthesize InSb NPs useful for various electronics applications

Summary

Introduction

Indium antimonide (InSb) is a well-known III-IV semiconductor with one of the smallest band gaps (~0.17 eV at 300 K) and the highest room-temperature electron mobility (~78,000 cm2/(Vs)[2]). InSb has a very small effective mass for electrons and has a large Bohr radius of ~65 nm. All these properties make InSb a good candidate for infrared detectors, magnetic sensors, cooling devices, thermoelectric power generation, high-speed field-effect transistors, and low-power device applications [1–4]. Lowdimensional InSb structures show good quantum confinement and various studies have been published on synthesis and characterization of InSb thin films and nano-wires [5–11]. On the other hand, InSb nanoparticles (NPs) have been rarely studied. The synthesis of low dimensional InSb structures has been challenging in general and problems like non-uniformity in size of NPs and aggregation of NPs have persisted. We present a comparatively straightforward method for synthesis of InSb NPs with reasonable control over NP aggregation

Methods

Results

Conclusion