Elucidating the local interfacial structure of highly photoresponsive carbon nanotubes/PbS-QDs based nanohybrids grown by pulsed laser deposition. (January 2016)

• Record Type: Journal Article
• Authors: Fujisawa, Kazunori; Ka, Ibrahima; Le Borgne, Vincent; Kang, Cheon-Soo; Kobayashi, Kensaku; Muramatsu, Hiroyuki; Hayashi, Takuya; Kim, Yoong Ahm; Endo, Morinobu; Terrones, Mauricio; El Khakani, My Ali
• Is Part Of: Carbon. Volume 96(2016)
• Page Start: 145
• Page End: 152
• Publication Date: 2016-01
• Subjects: Quantum dots -- Carbon nanotubes -- Interface -- Nanohybrids -- Photocurrent; Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2015.09.051
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: Carbon nanotubes (CNTs)/lead sulfide (PbS) quantum dots (QDs) nanohybrids have been synthesized through the controlled decoration of CNTs by PbS-QDs by means of the pulsed laser deposition technique. The size of the PbS-QDs and their surface coverage of the CNTs' surface are monitored through the number of laser ablation pulses. Here, while comparing both single-walled (SW) and double-walled (DW) CNTs based nanohybrids, focus is put on the investigation of their interfacial structure and the effect of inner tube. Anchoring PbS through direct sulfur-carbon chemical bonding between CNTs' outer wall and PbS-QDs, which are thought to be profitable for efficient charge transfer but not for charge transport along CNT's tube axis, are confirmed by Raman spectroscopy and X-ray photoelectron spectroscopy. In the case of double-walled CNTs (DWCNTs), inner tube remains unaffected by ablated PbS species, then it serves efficient conduction way for transferred photo-generated charges. This unique feature of the DWCNTs based nanohybrid, where the photocharges are generated by the chemically bonded PbS-QDs to the outer tube and then efficiently conveyed by the inner tube of the nanotubes, is highly likely at the origin of their significantly higher photo-activity (several hundred times than in SWCNTs-based nanohybrids).