Dual emission in asymmetric “giant” PbS/CdS/CdS core/shell/shell quantum dots

Anno: 2016

Autori: Zhao H., Sirigu G., Parisini A., Camellini A., Nicotra G., Rosei F., Morandi V., Zavelani-Rossi M., Vomiero A.

Affiliazione autori: CNR INO, SENSOR Lab, Via Branze 45, I-25123 Brescia, Italy;‎ Inst Natl Rech Sci, 1650 Blvd Lionel Boulet, Varennes, PQ J3X 1S2, Canada;‎ Politecn Milan, Dipartimento Fis, Piazza L da Vinci 32, I-20133 Milan, Italy; CNR IMM, Sez Bologna, Via Gobetti 101, I-40129 Bologna, Italy; ‎ CNR IMM, Sez Catania, Str VIII 5, I-95121 Catania, Italy;‎ Univ Elect Sci & Technol China, Inst Fundamental & Frontier Sci, Chengdu 610054, Peoples R China;‎ McGill Univ, Ctr Self Assembled Chem Struct, 801 Sherbrooke St West, Montreal, PQ H3A 0B8, Canada;‎ Politecn Milan, IFN CNR, Dipartimento Energia, Via Ponzio 34-3, I-20133 Milan, Italy;‎ Lulea Univ Technol, Dept Engn Sci & Math, S-97198 Lulea, Sweden

Abstract: Semiconducting nanocrystals optically active in the infrared region of the electromagnetic spectrum enable exciting avenues in fundamental research and novel applications compatible with the infrared transparency windows of biosystems such as chemical and biological optical sensing, including nanoscale thermometry. In this context, quantum dots (QDs) with double color emission may represent ultra-accurate and self-calibrating nanosystems. We present the synthesis of giant core/shell/shell asymmetric QDs having a PbS/CdS zinc blende (Zb)/CdS wurtzite (Wz) structure with double color emission close to the near-infrared (NIR) region. We show that the double emission depends on the excitation condition and analyze the electron-hole distribution responsible for the independent and simultaneous radiative exciton recombination in the PbS core and in the CdS Wz shell, respectively. These results highlight the importance of the driving force leading to preferential crystal growth in asymmetric QDs, and provide a pathway for the rational control of the synthesis of double color emitting giant QDs, leading to the effective exploitation of visible/NIR transparency windows.

Giornale/Rivista: NANOSCALE

Volume: 8 (7)      Da Pagina: 4217  A: 4226

Parole chiavi: SURFACE-RELATED EMISSION; IN-BULK NANOCRYSTALS; PBS NANOCRYSTALS; CHARGE-TRANSFER; SEMICONDUCTOR NANOCRYSTALS; COLLOIDAL NANOCRYSTALS; AUGER RECOMBINATION; SUPPRESSED BLINKING; INFRARED-EMISSION; 2-COLOR QUANTUM
DOI: 10.1039/c5nr08881j

Citazioni: 45
dati da “WEB OF SCIENCE” (of Thomson Reuters) aggiornati al: 2022-09-25
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