Growth and morphology of 0.80eV photoemitting indium nitride nanowires

Abstract

InN nanowires with high efficiency photoluminescence emission at 0.80 eV are reported for the first time. InN nanowires were synthesized via a vapor solid growth mechanism from high purity indium metal and ammonia. The products consist of only hexagonal wurtzite phase InN. Scanning electron microscopy showed wires with diameters of 50-100nm and having fairly smooth morphologies. High-resolution transmission electron microscopy revealed high quality, single crystal InN nanowires which grew in the <0001> direction. 2 M.C. Johnson et. al. Applied Physics LettersThe group-III nitrides have become an extremely important technological material over the past decade 1 HRTEM study unravels more detailed structural and morphological information. More importantly, the emission was extremely intense relative to the amount of material produced and the low incident laser power used (9mW) although a quantum efficiency cannot be determined from these measurements at this time. The PL emission from these nanowires was compared to high quality material thin films grown using MetalorganicChemical Vapor Deposition (MOCVD) 12 as shown in Figure 4. It is clear that these single crystalline nanowires have a very similar emission spectrum but with a narrower full width at half maximum (FWHM) indicating a higher quality material. Additionally, the peak emission is red-shifted by 30 meV which indicates a lower bandgap energy than the thin film.These PL results show the possibility of determining fundamental properties of InN from nanosize material eliminating many of the dislocations and impurities inherent to thin film materials. More detailed studies of the optical and transport properties of these InN nanowires are being investigated.In conclusion, we have developed a simple and reproducible method by which we can

Understanding the role of Si doping on surface charge and optical properties: Photoluminescence study of intrinsic and Si-doped InN nanowires

“…For InN:Si nanowires, the Si cell temperatures were ∼ 1250 • C and ∼ 1350 • C, respectively. Compared to the previous approaches in growing InN nanowires, 8,21,32,36,[47][48][49][50][51] in this experiment an In seeding layer (∼ 0.6 nm) was first deposited in situ onto Si (111) surface prior to the growth initiation, which can promote the formation and nucleation of InN nanowires. The detailed growth procedures were described elsewhere.…”

“…8,11,25,[31][32][33][34] Moreover, it has been generally observed that there exists a very high electron concentration (∼ 1 × 10 13−14 cm −2 ) at both the polar and nonpolar grown surfaces of InN films, 19,35 and the Fermi-level (E F ) is pinned deep into the conduction band at the surfaces; 19,20,29,30 similar electron accumulation profile has also been measured at the lateral nonpolar grown surfaces of [0001]-oriented wurtzite InN nanowires. 8,11,21,22,25,36 In this regard, significant efforts have been devoted to understanding the fundamental surface charge properties of InN. 20,23,27,29,30,[37][38][39] The electron accumulation at polar InN surface has been explained by the presence of large density of the occupied In-In bond states above the conduction band minimum (CBM), 23 as well as the unusual positioning of the branch point energy (E B ) well above the CBM at the Γ-point, which allows donor-type surface states to exist in the conduction band; 20 for polar InN surface, theoretical studies agree well with experiments.…”

Growth direction modulation and diameter-dependent mobility in InN nanowires

“…In recent years, research interest has been directed towards studying InN nanowires (NWs) which exhibit many fascinating properties of InN thin films. Although several studies on InN NW synthesis [9], photoluminescence [10], electroluminescence [11], metal contacts [12], field effect transistors (FETs) [13] and THz emission [14] have been reported, many interesting properties of InN NWs have not yet been adequately understood. Slow progress in research on InN NWs can be attributed partly to synthesis issues such as low growth rate (only a few microns per hour) and poor material quality [15][16][17][18].…”

Growth of InN quantum dots to nanorods: a competition between nucleation and growth rates

“…Growth mechanism of InN nanostructures from In 2 O 3 powder is explained based on the VS mechanism. Earlier reports could not provide an appreciable explanation for the temperature dependent evolution of morphology in InN nanostructures [13,15]. We correlate the evolution of morphology with the nucleation rate and growth rates of newly grown phase during the conversion of In 2 O 3 to InN at a given temperature.…”

“…Even though InN has difficulties in synthesis, reports are available on the growth of InN nanorods (NRs) or nanowires (NWs) with different techniques like molecular beam epitaxy (MBE) [4,5], guidedstream thermal chemical vapor deposition (CVD) [11], controlledcarbonitridation reaction route [12], and thermal CVD [13][14][15]. Among these techniques CVD is a commercially viable technique for controlled and large scale synthesis.…”