High-Temperature Pb Doping of SnO₂ and Growth Limitations of Pb_xSn_1–xO₂ Nanowires Versus Low-Temperature Growth of Pb_xSn_1–xO for Energy Storage and Conversion

Abstract

Pb doping of SnO 2 nanowires grown by the vapor−liquid− solid mechanism on 1 nm Au/Si has been investigated between 500 and 1000 °C via the reaction of Sn-containing Pb with O 2 at 10 −1 mbar. The SnO 2 nanowires have diameters of 50 nm, lengths up to 100 μm, and a tetragonal rutile crystal structure, but they do not contain Pb because of its significant depletion during the temperature ramp and re-evaporation from the surface of the SnO 2 nanowires. Consequently, we do not observe a semiconductor to semimetal transition and band gap narrowing. Instead, the Pb reacts with O 2 , leading to the deposition of PbO directly on Si but not on the SnO 2 nanowires, which have carrier densities of ≈10 16 cm −3 . Furthermore, onedimensional growth was completely suppressed by increasing the amount of Pb in Sn. As such, Pb doping of SnO 2 and the growth of Pb x Sn 1−x O 2 nanowires is difficult, if not impossible, because PbO 2 nanowires cannot be grown by the vapor−liquid−solid mechanism irrespective of the growth temperature. In contrast, we find that the composition of Pb x Sn 1−x O nanostructures may be tuned over a broad range by lowtemperature growth at 400 °C. We discuss the properties and prospects of this ternary oxide for energy conversion and storage.

Insight into Copper Doping Ratio on Optoelectronics Performance of Two-Dimensional Cu-Doped SnO2 Nanosheets: an Experiment and DFT Study

“…Ao et al 36 engineered and fabricated silicon-doped SnO 2 nanorods that form a novel sandwich structure with carbon-sealed reduced GO and exhibit excellent electrical properties, such as extraordinary reaction rate, super-high capacitance, as well as cyclic stability and high conductivity. Zervos et al 37 investigated the growth mechanism of Pb-doped SnO 2 nanowires at different temperatures and their energy conversion properties. Medhi et al 38 successfully synthesized Sb,Zn-doped SnO 2 nanoparticles, which effectively regulated the band gap of SnO 2 nanoparticles and expanded its appropriate application in the field of optoelectronics.…”

Vapor–liquid–solid growth and properties of one dimensional PbO and PbO/SnO2 nanowires

“…The PbO 2 NWs of Pan et al 22 were collected on 10 mm  60 mm Al 2 O 3 at lower temperatures but these were not explicitly specified. Recently, we tried to obtain PbO 2 NWs via the vapor-liquid-solid (VLS) mechanism and the reaction of Pb with O 2 at 800 1C 23 using Au as a catalyst but instead we obtained PbO, which is a semiconductor with an intermediate direct energy band gap of E1.8 eV that is n-type when it contains an excess of Pb and p-type when it is O-rich. 24 More specifically, the reaction of Pb with O 2 leads to the deposition of PbO layers but we did not obtain any nanowires.…”