PbSe nanocrystal shape development: oriented attachment at mild conditions and microwave assisted growth of nanocubes

Sliem, Mahmoud A.; Chemseddine, A.; Bloeck, Ulrike; Fischer, Roland A.

doi:10.1039/c0ce00106f

Cited by 38 publications

(38 citation statements)

References 34 publications

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“…We note a similar effect reported in PbSe nanoparticle films where hydrous methanol was used to replace Pb(oleate) 2 . 15 In that work, partial fusion of nanoparticles was reported upon ligand exchange, which we do not observe with the treatment presented here.…”

Section: Resultscontrasting

confidence: 64%

Nonmonotonic Size Dependence in the Hole Mobility of Methoxide-Stabilized PbSe Quantum Dot Solids

et al. 2013

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We present a facile procedure to fabricate p-type PbSe-based quantum dot solids with mobilities as large as 0.3 cm2 V–1 s–1. Upon partial ligand exchange of oleate-capped PbSe quantum dots with the methoxide ion, we observe a pronounced red shift in the excitonic transition in conjunction with a large increase in conductivity. We show that there is little correlation between these two phenomena and that the electronic coupling energy in PbSe quantum dot solids is much smaller than often assumed. However, we observe for the first time a nonmonotonic size dependence of the hole mobility, illustrating that coupling can nonetheless be dominant in determining the transport characteristics. We attribute these effects to a decrease in charging energy and interparticle spacing, leading to enhanced electronic coupling on one hand and enhanced dipole interactions on the other hand, which is held responsible for the majority of the red shift.

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Section: Resultscontrasting

confidence: 64%

Nonmonotonic Size Dependence in the Hole Mobility of Methoxide-Stabilized PbSe Quantum Dot Solids

et al. 2013

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“…Indeed, depending on the temperature and MW power, the NC size could be easily tuned over the 2–5 nm range in short times (<20 min) with elevate degree of monodispersity ( σ <5–7 %), as judged from the sharp exciton absorption features and narrow band‐edge photoluminescence peaks 287–289. In line with these achievements, it was reported that high‐quality size‐tunable CdS, CdSe, CdTe (Figure 8 a–d), PbS and PbSe NCs (Figure 8 h) could be prepared in MW‐transparent low‐boiling alkanes under autogenic pressure conditions by exploiting the preferential MW energy coupling to polarizable phosphine‐chalcogenide precursors, the activation of which entirely governed the critical nucleation and growth stages 288–292. In all aforementioned cases remarkable practical advantages were evidenced.…”

Section: Examples Of Microwave‐assisted Nanocrystal Synthesesmentioning

confidence: 56%

Microwave‐Assisted Synthesis of Colloidal Inorganic Nanocrystals

et al. 2011

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Colloidal inorganic nanocrystals stand out as an important class of advanced nanomaterials owing to the flexibility with which their physical-chemical properties can be controlled through size, shape, and compositional engineering in the synthesis stage and the versatility with which they can be implemented into technological applications in fields as diverse as optoelectronics, energy conversion/production, catalysis, and biomedicine. The use of microwave irradiation as a non-classical energy source has become increasingly popular in the preparation of nanocrystals (which generally involves complex and time-consuming processing of molecular precursors in the presence of solvents, ligands and/or surfactants at elevated temperatures). Similar to its now widespread use in organic chemistry, the efficiency of "microwave flash heating" in dramatically reducing overall processing times is one of the main advantages associated with this technique. This Review illustrates microwave-assisted methods that have been developed to synthesize colloidal inorganic nanocrystals and critically evaluates the specific roles that microwave irradiation may play in the formation of these nanomaterials.

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“…Previous results published by Sliem M.A. et al 30 report that higher loadings of oleate molecules on PbSe nanoparticles correlates to a higher integrated intensity of all the peaks associated with the methyl and methylene groups. When a higher concentration of lead precursor is used, it is observed that the integrated intensity of the peaks associated with the methyl and methylene groups increases, along with the intensity of the peak directly associated with the lead oleate (1572 cm −1 ).…”

Section: Resultsmentioning

confidence: 91%

Aberration Corrected STEM Study of the Surface of Lead Chalcogenide Nanoparticles

et al. 2014

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In this contribution, we report on the microscopic and spectroscopic characterization of lead chalcogenide nanoparticles. PbSe and PbTe nanoparticles were synthesized by chemical methods, using different molar ratios of Pb, Se, and Te precursors and varying the reaction time. These nanoparticles were characterized by means of transmission electron microscopy and their related techniques: electron diffraction, energy dispersive X-ray spectroscopy (EDXS), electron energy loss spectroscopy (EELS), and aberration corrected scanning transmission electron microscopy (AC-STEM), to obtain information related to their morphology, crystal structure, and composition. They were also characterized by means of Fourier transform infrared (FTIR) absorption spectroscopy to assess the functional groups found on the surface of the nanoparticles, depending on the synthesis conditions. The results obtained showed that the synthesized nanoparticles always display a higher concentration of Pb compared to that of the chalcogen. Moreover, the final concentration of Pb depended on the original ratio between the Pb precursor and the chalcogen precursor used in the synthesis. These variations in the composition influenced the FTIR absorption characteristics of the nanoparticles. EDXS, EELS, and AC-STEM results indicate that this excess of Pb is located on the surface of the nanoparticles, particularly in the amorphous capping layer. These results as well as those obtained from FTIR spectroscopy suggest that the protective layer is mostly made of lead oleate.

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PbSe nanocrystal shape development: oriented attachment at mild conditions and microwave assisted growth of nanocubes

Cited by 38 publications

References 34 publications

Nonmonotonic Size Dependence in the Hole Mobility of Methoxide-Stabilized PbSe Quantum Dot Solids

Nonmonotonic Size Dependence in the Hole Mobility of Methoxide-Stabilized PbSe Quantum Dot Solids

Microwave‐Assisted Synthesis of Colloidal Inorganic Nanocrystals

Aberration Corrected STEM Study of the Surface of Lead Chalcogenide Nanoparticles

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