Charge transport in mixed CdSe and CdTe colloidal nanocrystal films

Geyer, Scott M.; Porter, Venda J.; Halpert, Jonathan E.; Mentzel, Tamar; Kastner, M. A.; Bawendi, Moungi G.

doi:10.1103/physrevb.82.155201

Cited by 51 publications

(47 citation statements)

References 25 publications

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“…For example, QD thin films have been incorporated as the semiconductor active layer in electronic transistors and circuits [5][6][7][8][9]; optoelectronic solar photovoltaics [10][11][12][13][14][15], photodetectors [16][17][18][19], and light-emitting diodes [20,21]; and thermoelectric devices [22]. To design QDs and QD thin films for integration into devices, the electronic structure and the charge Density of States Energy E F…”

Section: Introductionmentioning

confidence: 99%

The effects of inorganic surface treatments on photogenerated carrier mobility and lifetime in PbSe quantum dot thin films

et al. 2016

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We used flash-photolysis, time-resolved microwave conductivity (TRMC) to probe the carrier mobility and lifetime in PbSe quantum dot (QD) thin films treated with solutions of the metal salts of Na 2 Se and PbCl 2 . The metal salt treatments tuned the Pb:Se stoichiometry and swept the Fermi energy throughout the QD thin film bandgap. A stoichiometric imbalance favoring excess Se heavily p-doped the QD thin film, shifted the Fermi energy toward the valence band, and yielded the highest TRMC mobility and lifetime. Introducing Pb first compensated the p-doping and shifted the Fermi level through mid-gap, decreasing the TRMC mobility. Further Pb addition created an excess of Pb, n-doped the QD thin film, moved the Fermi level to near the conduction band, and again increased the TRMC mobility. The increase in TRMC mobility as the Fermi energy was shifted toward the band edges by non-stoichiometry is consistent with the QD thin film density of states. 2 Graphical abstract Keywords Time-resolved microwave conductivity; quantum dot; doping; spectroscopy; optoelectronic; lead selenide Highlights  Na 2 Se and PbCl 2 treatments modified the surface chemistry of PbSe quantum dots  Excess Se (Pb) p-doped (n-doped) PbSe quantum dot thin films  Carrier mobility and lifetime were studied using time-resolved microwave conductivity  Mobility increased as the Fermi level approached the band edges

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Section: Introductionmentioning

confidence: 99%

The effects of inorganic surface treatments on photogenerated carrier mobility and lifetime in PbSe quantum dot thin films

et al. 2016

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“…This structure is referred to as nanobarbell or nanodumbbell (ND) 6 and presents an inhomogeneous confining potential and promising technological applications. 7 Among the exotic physical regimes difficult to attain in natural atoms but straightforwardly reachable in artificial heterostructures, we may mention the Wigner crystal. In 1934 Wigner predicted that, below a critical electron density, the electron gas crystallizes and forms a lattice of electrons arranged in precise classical configurations.…”

Section: Introductionmentioning

confidence: 99%

Configuration interaction approach to Fermi liquid–Wigner crystal mixed phases in semiconductor nanodumbbells

Ballester¹,

Movilla²,

Escartín³

et al. 2012

Journal of Applied Physics

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Full configuration interaction calculations demonstrate the existence of mixed correlation phases in truly three-dimensional elongated nanocrystals subject to inhomogeneous spatial confining potentials. In such phases, the electron density behaves like a Fermi liquid in some regions, while, simultaneously, other more dilute regions display the typical quasi-classical Wigner distribution. The present results confirm and strengthen previous local spin-density functional theory predictions [Ballester et al., Phys. Rev. B 82, 115405 (2010)]. Additionally, simulation of the in-plane and z-polarized modes of the absorption spectra reveals the different correlation regimes occurring in these systems.

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“…What causes the transport regime prevail depends on the structural and morphological properties of the QD thin films. Despite its importance for practical applications, there has been relatively little work done on charge transport in the QD thin films [1]. Experimental investigation of thermal transport in such structures has also just begun [14].…”

Section: Introductionmentioning

confidence: 99%

“…They can be fabricated near room temperature and scalable to large-area substrates [1][2][3]. Various artificially nanostructured materials have also become available which possess large transition dipole moments and consequently strong optical absorption [4].…”

Section: Introductionmentioning

confidence: 99%

Structural, optical, and electrical properties of thioglycolic acid-capped CdTe quantum dots thin films

et al. 2013

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Water-soluble cadmium telluride (CdTe) quantum dots (QDs) were synthesized using thioglycolic acid as capping agent; this reaction was carried out at pH = 10.2 and refluxed at 100°C for 18 h. The CdTe QDs prepared at various reflux times from 1 to 18 h were coated on the glass substrates to obtain thin films of the CdTe QDs with the same thickness. The CdTe thin films were characterized by X-ray diffraction, ultraviolet-vis spectroscopy, and photoluminescence spectroscopy. The absorption thresholds of the CdTe thin films are blueshifted by about 0.65 eV with respect to the bulk value (1.5 eV), due to the quantum size effect as expected from the nanocrystalline nature of the CdTe QDs. X-ray diffraction showed that the films consisted of small CdTe nanocrystallites, 2.91 to 3.57 nm in size, showing quantum size effects. The effects of temperature on the electrical properties of the films were studied in detail. Electrical resistivity measurements were carried out for different films in the temperature range from 343 to 463 K. It is shown that activation energy increases by increasing the reflux time.

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Charge transport in mixed CdSe and CdTe colloidal nanocrystal films

Cited by 51 publications

References 25 publications

The effects of inorganic surface treatments on photogenerated carrier mobility and lifetime in PbSe quantum dot thin films

The effects of inorganic surface treatments on photogenerated carrier mobility and lifetime in PbSe quantum dot thin films

Configuration interaction approach to Fermi liquid–Wigner crystal mixed phases in semiconductor nanodumbbells

Structural, optical, and electrical properties of thioglycolic acid-capped CdTe quantum dots thin films

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