A layer-nanostructured assembly of PbS quantum dot/multiwalled carbon nanotube for a high-performance photoswitch.
A layered nanostructure of a lead sulfide (PbS) quantum dot (QD)/multi-walled carbon nanotube (MWNT) hybrid was prepared by the electrostatic assembly after the phase transfer of PbS QDs from an organic to an aqueous phase. Well-crystallized PbS QDs with a narrow diameter (5.5 nm) was mono-dispersed on the sidewalls of MWNT by the electrostatic adsorption. Near-infrared absorption of PbS/MWNT nanostructures was improved and controlled by the packing density of PbS QDs. Efficient charge transfer between PbS and MWNT at the interface resulted in a remarkable quenching of photoluminescence up to 28.6% and a blue-shift of emission band by 300 nm. This feature was facilitated by band energy levels based on the intimate contact through the electrostatic interaction. Two-terminal devices using PbS/MWNT nanostructures showed an excellent on/off switching photocurrent and good stability during 20 cycles under light illumination due to electron transfer from PbS to MWNT. The photoswitch exhibited a high photo sensitivity up to 31.3% with the photocurrent of 18.3 μA under the light of 3.85 mW/cm(2), which outperformed many QD/carbon-based nanocomposites. Results indicate that the electrostatic layered assembly of QD/MWNT nanostructure is an excellent platform for the fabrication of high-performance optoelectronic devices.
School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, China.
Wei
W
Feng
School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, China.
Chengqun
C
Qin
School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, China.
Yongtao
Y
Shen
School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, China.
Yu
Y
Li
School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, China.
Wen
W
Luo
School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, China.
Haoran
H
An
School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, China.
Yiyu
Y
Feng
D004579:Electron Transport; D007854:Lead / Q000737:chemistry*; D008027:Light; D053761:Nanocomposites; D049329:Nanostructures; D037742:Nanotubes, Carbon / Q000737:chemistry*; D045663:Quantum Dots / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry*
D037742:Nanotubes, Carbon; D013440:Sulfides; C018391:lead sulfide; D007854:Lead