title: Effect of mercaptocarboxylic acids on luminescent properties of CdTe quantum dots.
abstract: CdTe quantum dots (QDs) were prepared in an aqueous solution using various mercaptocarboxylic acids, such as 3-mercaptopropionic acid (MPA) and thioglycolic acid (TGA), as stabilizing agents. The experimental result indicated that these stabilizing agents played an important role for the properties of the QDs. Although both TGA and MPA-capped CdTe QDs exhibited the tunable photoluminescence (PL) from green to red color, the TGA-capped QDs revealed a higher PL quantum yield (QY) up to 60% than that of MPA-capped QDs (up to 50%) by using the optimum preparation conditions, such as a pH value of ~11.2 and a TGA/Cd molar ratio of 1.5. PL lifetime measurements indicate that the TGA-capped QDs exhibited a short average lifetime while the MPA-capped QDs revealed a long one. Furthermore, the average lifetime of the TGA-capped QDs increased with the increase of the QDs size, while a decreased lifetime for the MPA-capped QDs was obtained. This means that the PL lifetime depended strongly on the surface state of the CdTe QDs. These results should be utilized for the preparation and applications of QDs.
authors.affiliation: School of Material Science and Engineering, University of Jinan, 250022, Jinan, People's Republic of China.
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Yuan
authors.forename: Aiyu
authors.initials: A
authors.lastname: Zhang
authors.forename: Yongqiang
authors.initials: Y
authors.lastname: Cao
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.forename: Yuanna
authors.initials: Y
authors.lastname: Zhu
authors.forename: Ping
authors.initials: P
authors.lastname: Yang
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D049408:Luminescent Agents / Q000737:chemistry*; D008163:Luminescent Measurements; D055620:Optical Phenomena; D010316:Particle Size; D045663:Quantum Dots; D013691:Tellurium / Q000737:chemistry*; D013864:Thioglycolates / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D002264:Carboxylic Acids; D049408:Luminescent Agents; D013864:Thioglycolates; D014867:Water; C017487:2-mercaptoacetate; D013691:Tellurium; C028337:cadmium telluride