Three Synthetic Routes to Single-Crystalline PbS Nanowires with Controlled Growth Direction and Their Electrical Transport Properties

Abstract

Single-crystalline rock-salt PbS nanowires (NWs) were synthesized using three different routes; the solvothermal, chemical vapor transport, and gas-phase substitution reaction of pregrown CdS NWs. They were uniformly grown with the [100] or [110], [112] direction in a controlled manner. In the solvothermal growth, the oriented attachment of the octylamine (OA) ligands enables the NWs to be produced with a controlled morphology and growth direction. As the concentration of OA increases, the growth direction evolves from the [100] to the higher surface-energy [110] and [112] directions under the more thermodynamically controlled growth conditions. In the synthesis involving chemical vapor transport and the substitution reaction, the use of a lower growth temperature causes the higher surface-energy growth direction to change from [100] to [110]. The high-resolution X-ray diffraction pattern and X-ray photoelectron spectroscopy results revealed that a thinner oxide-layer was produced on the surface of the PbS NWs by the substitution reaction. We fabricated field effect transistors using single PbS NW, which showed intrinsic p-type semiconductor characteristics for all three routes. For the PbS NW with a thinner oxide layer, the carrier mobility was measured to be as high as 10 cm(2) V(-1) s(-1).

Shape effect on the valley splitting in lead selenide nanowires

“…They include colloidal synthesis [10], solution-liquid-solid [12] methods and even oriented attachment of lead salt nanocrystals [8]. Nowadays it is not only possible to grow a nanowire a few nm thin [13], but also to control its shape [14][15][16], size [17] and growth direction [18]. Nonetheless, theoretical modelling of lead chalcogenide NWs is quite challanging due to the multivalley band structure and strong intervalley coupling in these systems.…”

Hybrid Polyfluorene-Based Optoelectronic Devices

“…More recently, the self-assembly of lead-salt nanocrystals into more complex nanowire (1D) (Cho et al, 2005;Jang et al, 2010;Koh et al, 2010), monolayer (2D) (Anikeeva et al, 2007(Anikeeva et al, , 2008Coe-Sullivan et al, 2003;Konstantatos et al, 2005;Steckel et al, 2003; and nanocrystalline films and superlattices structures (3D) (Hanrath et al, 2009;Klem et al, 2007Klem et al, , 2008Luther et al, 2008;Talapin et al, 2005) with a wide range of most promising optoelectronic properties has rapidly become a very active field of research, largely due to its facile solution-based processing. Recently, exciting reports such as the observation of superb multiple-exciton generation efficiencies (Sargent, 2009;Sukhovatkin et al, 2009), highly-efficient hot-electron injection (Tisdale et al, 2010), and cold-exciton recycling (Klar et al, 2009), have propelled nanocrystalline lead-chalcogenide film structures to the forefront of cutting-edge research (M. S. Kang et al, 2009;W.…”

Nanostructured Photocathodes for Infrared Photodetectors and Photovoltaics

“…It is even more significant in optoelectronics, where charge transfer and photon absorption/ emission are coupled, and interfaces should facilitate efficient charge transfer between the light absorbing semiconductor layer(s) and its contacting electrodes. 9 Unintentionally doped, as-deposited p-type NWs were previously fabricated from CoO, 10 NiO 11 and PbS 12 CuSCN seed layers were deposited at −500 mV vs Ag/AgCl, potentiostatically or using the pulse sequence t on =2 sec, t off =1 sec, for an overall time of 2700 sec. Inefficient charge transport in absorber films limits the absorber layer thickness, hence limiting its absorption.…”