Microwave mediated synthesis of semiconductor quantum dots

Abstract

Colloidal quantum dots (QD) have tuneable optoelectronic properties and can be easily handled by simple solution processing techniques, making them very attractive for a wide range of applications. Over the past decade synthesis of morphology controlled high quality (crystalline, monodisperse) colloidal QDs by thermal decomposition of organometallic precursors has matured and is well studied. Recently, synthesis of colloidal QDs by microwave irradiation as heating source is being studied due to the inherently different mechanisms of heat transfer, when compared to solvent convection based heating. Under microwave irradiation, polar precursor molecules directly absorb the microwave energy and heat up more efficiently. Here we report synthesis of colloidal II‐VI semiconductor QDs (CdS, CdSe, CdTe) by microwave irradiation and compare it with conventional synthesis based on convection heating. Our findings show that QD synthesis by microwave heating is more efficient and the chalcogenide precursor strongly absorbs the microwave radiation shortening the reaction time and giving a high reaction yield (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Composition Tuning of Nanostructured Binary Copper Selenides through Rapid Chemical Synthesis and Their Thermoelectric Property Evaluation

“…Recent studies show that synthesis route may dramatically influence and contribute to TE properties of nanomaterials [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. Among these methods, solvothermal, thermolysis [ 22 , 29 , 30 , 31 , 32 ] melting and annealing [ 24 , 26 , 33 , 34 ], mechanical alloying [ 35 , 36 , 37 ], co-precipitation and solution reduction [ 38 ], and microwave (MW)-assisted synthesis [ 14 , 32 , 39 ] have been reported in recent decades. MW-assisted synthesis has been reported for the synthesis of (BiSb) 2 (TeSe) 3 systems, where the produced quantities per batch have been rather limited.…”

One-pot synthesis of high quality CdS nanocrystals by microwave irradiation in an organic phase: a green route for mass production

“…The result matches well with Afrasiabi's research. 40 One explanation for gaining larger sized QDs by microwave heating compared to the conventional heating could be that the nucleation event happens in an earlier stage since the enhanced rate of monomer generation by microwave heating causes a faster supersaturation of monomers in the system. So assuming that the QDs are synthesized at the same reaction time in both processes, larger nanocrystals can be produced by microwave heating.…”

“…A few reports have recently detailed the microwave irradiation route for good-quality semiconductor nanocrystals either using expensive Cd chemicals, toxic solvents (TOP, TOPO, TBP) or under a protective atmosphere. [38][39][40] In this paper, we developed a novel microwave irradiation one-pot method for synthesis of high quality CdS QDs by simply mixing CdO, S powder, oleic acid, and 1-octadecene in open air. Cd and S precursors were pre-synthesized for the rst time by microwave heating.…”