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Studies of interaction of amines with TOPO/TOP capped CdSe quantum dots: Role of crystallite size and oxidation potential

IR@NPL: CSIR-National Physical Laboratory, New Delhi

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Title Studies of interaction of amines with TOPO/TOP capped CdSe quantum dots: Role of crystallite size and oxidation potential
 
Creator Sharma, Shailesh N.
Sharma, Himani
Singh, Gurmeet
Shivaprasad, S. M.
 
Subject Materials Science
Physics
 
Description This work reports the interaction of aliphatic (triethyl amine, butyl amine) and aromatic amines (PPD, aniline) with CdSe quantum dots of varied sizes. The emission properties and lifetime values of CdSe quantum dots were found to be dependent on the oxidation potential of amines and crystallite sizes. Smaller CdSe quantum dots (size similar to 5 nm) ensure better surface coverage of amines and hence higher quenching efficiency of amines could be realized as compared to larger CdSe quantum dots (size similar to 14 nm). Heterogeneous quenching of amines due to the presence of accessible and inaccessible set of CdSe fluorophores is indicated. PPD owing to its lowest oxidation potential (similar to 0.26 V) has been found to have higher quenching efficiency as compared to other amines TEA and aniline having oxidation potentials similar to 0.66 and >1.0 V, respectively. Butyl amine on the other hand, plays a dual role: its post-addition acts as a quencher for smaller and enhances emission for larger CdSe quantum dots, respectively. The beneficial effect of butyl amine in enhancing emission intensity could be attributed to enhance capping effect and better passivation of surface-traps.
 
Publisher Elsevier
 
Date 2008
 
Type Article
PeerReviewed
 
Format application/pdf
 
Identifier http://npl.csircentral.net/2110/1/238.pdf
Sharma, Shailesh N. and Sharma, Himani and Singh, Gurmeet and Shivaprasad, S. M. (2008) Studies of interaction of amines with TOPO/TOP capped CdSe quantum dots: Role of crystallite size and oxidation potential. Materials Chemistry and Physics, 110 (2-3). pp. 471-480. ISSN 0254-0584
 
Relation http://npl.csircentral.net/2110/