CdSe Nanowire/Fullerene Nanocomposite Photoelectrode: Charge Separation and Photoelectrochemical Behavior

摘要

The fabrication of semiconductor nanocomposites with a staggered band-edge alignment has been widely adapted to facilitate charge separation, thus harnessing more photons in light-harvesting systems. To date, a variety of semiconductor nanocomposites have been developed ranging from purely inorganic nanocomposites to organic/inorganic hybrid analogues. Among the organic/inorganic hybrid nanocomposites, semiconductor/fullerene (C_(60)) based nanohetero-structures have been widely investigated due to the excellent electron-accepting ability of C_(60). While a wide variety of QD/C_(60) hybrid nanocomposites have been reported, no attempt has been made toward combining semiconductor nanowires (NWs) with C_(60) to date. In comparison to QDs, semiconductor NWs can be potentially advantageous in several respects when they serve as a light harvester because of their asymmetric geometry. Superior intrinsic properties induced by the one-dimensional nanostructure, such as higher charge carrier mobility and larger absorption cross section, are representative benefits they can provide.15'16 In this study, we have for the first time examined the photo-electrochemical performance of photoelectrodes comprised of GdSe NWs and CdSe NWs/C_(60) nanocomposite and have investigated the beneficial effect of C_(60) as a coupling material. We found that the CdSe NWs/C_(60) photoelectrode showed considerably enhanced performance than its counterpart, CdSe NWs. To elucidate the improvement, electron transfer kinetics and optical properties of the nanocomposite were investigated in this work.