Assembly of CdS quantum dots onto mesoscopic TiO2 films for quantum dot-sensitized solar cell applications

摘要: Colloidal cadmium sulfide (CdS) quantum dots (QDs) were prepared and surface modified by mercaptosuccinic acid (MSA) to render a with carboxylic groups (MSA?CdS). The MSA?CdS QDs then assembled onto bare TiO2 mesoporous films using the groups/TiO2 interaction. film was also 3-mercaptopropyl trimethoxysilane (MPTMS) or 3-aminopropyl-methyl diethoxysilane (APMDS) prepare, respectively, thiol (?SH) amino (?NH2) terminated for binding CdS QDs. experimental results showed that MPTMS-modified has highest adsorption rate amount QDs, attributable strong thiol/CdS In contrast, incorporated of on are much lower than silane-modified films. incident photon-to-current conversion efficiency (IPCE) obtained CdS-sensitized electrode about 20% (at 400?nm) TiO2, 13% MPTMS?TiO2, 6% APMDS?TiO2. current?voltage measurement under dark conditions reveals higher current MPTMS-?and APMDS-modified electrodes, indicating coverage ratio these This result is attributed fast bottleneck mesopore which inhibits transport deep into inner region pore. For film, but energy indicates formation better-covered monolayer. moderate acid/TiO2 interaction responsible efficient assembly