Broad compositional tunability of indium tin oxide nanowires grown by the vapor-liquid-solid mechanism

Abstract

Indium tin oxide nanowires were grown by the reaction of In and Sn with O2 at 800 °C via the vapor-liquid-solid mechanism on 1 nm Au/Si(001). We obtain Sn doped In2O3 nanowires having a cubic bixbyite crystal structure by using In:Sn source weight ratios > 1:9 while below this we observe the emergence of tetragonal rutile SnO2 and suppression of In2O3 permitting compositional and structural tuning from SnO2 to In2O3 which is accompanied by a blue shift of the photoluminescence spectrum and increase in carrier lifetime attributed to a higher crystal quality and Fermi level position.

Electrical, structural, and optical properties of sulfurized Sn-doped In2O3 nanowires

“…We do not observe the fluorite structure of In x Sn y O 3.5 as shown recently by Meng et al [19] who observed a flux-induced crystal phase transition in the VLS growth of Sn-doped In 2 O 3 NWs. The PL of the Sn-doped In 2 O 3 NWs was found to be broad with a maximum at λ = 500 nm or 2.5 eV that shifts to 450 nm or ≈2.8 eV upon reducing the content of Sn to 1 % which also results into an increase in the carrier lifetime as shown previously by time-resolved PL [11]. The PL of the as-grown Sn-doped In 2 O 3 NWs at 2.8 eV, which is shown in Fig.…”

“…1a while their lengths reached up to 100 μm. We have shown previously that the Sn-doped In 2 O 3 NWs have the cubic bixbyite crystal structure of In 2 O 3 as confirmed by GIXD but also by high resolution transmission electron microscopy (HRTEM) analysis which showed that the lattice spacing is equal to 0.718 nm and corresponds to the d-spacing of the {−1,1,0} crystallographic planes of the cubic bixbyite crystal structure of In 2 O 3 [11]. However, we also observed the formation of SnO 2 nanoparticles with a tetragonal rutile crystal structure on the surface of the Sn-doped In 2 O 3 NWs as shown by the inset of Fig.…”

“…Sn-doped In 2 O 3 NWs were grown by the VLS mechanism on 1 nm Au/Si(001) at 800°C using 1-5 % Sn [11]. A typical SEM image of the Sn-doped In 2 O 3 NWs is shown in Fig.…”

“…Sn-doped In 2 O 3 NWs were grown on Si(001) and fused silica by low-pressure chemical vapor deposition (LPCVD) described in detail elsewhere [11]. Square samples of Si and fused silica ≈7 × 7 mm were cleaned sequentially in trichloroethylene, methanol, acetone, isopropanol, rinsed with de-ionized water, dried with nitrogen, and coated with ≈1 nm of Au.…”

“…Recently, we carried out a systematic investigation into the growth and properties of Sn-doped In 2 O 3 or indium tin oxide (ITO) NWs grown on Si by the vapor-liquidsolid (VLS) mechanism [11] which may be converted to metal oxysulfide (MOxS) NWs with different properties by post growth processing under H 2 S that is useful for NWSCs. It has been shown that bulk β-In 2 S 3-3x O 3x has an optical band gap that varies from 2.1 eV in pure β-In 2 S 3 to 2.9 eV when it contains 8.5 at.% of oxygen and has been proposed as an alternative to CdS buffer layers in CuIn x Ga 1-x Se 2 solar cells [12,13].…”