On the non-linear I–V characteristics of dc magnetron sputtered TiO2 thin films

Stamate, Marius

doi:10.1016/s0169-4332(02)01130-3

Cited by 37 publications

(13 citation statements)

References 9 publications

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“…In contrast, these authors indicated that conductivity in R was through excitations of small polaronic states (see below), resulting in m e values of ∼20m 0 (based on references in [110]). Their assessment of m e in A being ∼m 0 is consistent with measurements by other groups [417,418] for thin A films and by DFT theory [413], although one report places m e > 10m 0 for A [127]. As yet, there appear to be no measurements reported on high quality single crystal A.…”

Section: Carrier Effective Masssupporting

confidence: 83%

A surface science perspective on TiO2 photocatalysis

Henderson

2011

Surface Science Reports

1,872

1,634

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a b s t r a c tThe field of surface science provides a unique approach to understanding bulk, surface and interfacial phenomena occurring during TiO 2 photocatalysis. This review highlights, from a surface science perspective, recent literature that provides molecular-level insights into photon-initiated events occurring at TiO 2 surfaces. Seven key scientific issues are identified in the organization of this review. These are: (1) photon absorption, (2) charge transport and trapping, (3) electron transfer dynamics, (4) the adsorbed state, (5) mechanisms, (6) poisons and promoters, and (7) phase and form. This review ends with a brief examination of several chemical processes (such as water splitting) in which TiO 2 photocatalysis has made significant contributions in the literature.

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Section: Carrier Effective Masssupporting

confidence: 83%

A surface science perspective on TiO2 photocatalysis

Henderson

2011

Surface Science Reports

1,872

1,634

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“…Monticone et al take the anatase TiO 2 electron effective mass to be equal to m e = 10 m 0 [7]. On the one hand, Pascual and co-workers obtained m e = 3 m 0 [8], whereas on the other hand Stamate recently reported a value of m e = (0.71-1.26) m 0 [9].…”

Section: Introductionmentioning

confidence: 99%

A comparative study of the electrical properties of TiO₂films grown by high-pressure reactive sputtering and atomic layer deposition

Dueñas

Castán

García

et al. 2005

Semicond. Sci. Technol.

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Oxide-semiconductor interface quality of high-pressure reactive sputtered (HPRS) TiO 2 films annealed in O 2 at temperatures ranging from 600 to 900 • C, and atomic layer deposited (ALD) TiO 2 films grown at 225 or 275 • C from TiCl 4 or Ti(OC 2 H 5 ) 4 , and annealed at 750 • C in O 2 , has been studied on silicon substrates. Our attention has been focused on the interfacial state and disordered-induced gap state densities. From our results, HPRS films annealed at 900 • C in oxygen atmosphere exhibit the best characteristics, with D it density being the lowest value measured in this work (5-6 × 10 11 cm −2 eV −1 ), and undetectable conductance transients within our experimental limits. This result can be due to two contributions: the increase of the SiO 2 film thickness and the crystallinity, since in the films annealed at 900 • C rutile is the dominant crystalline phase, as revealed by transmission electron microscopy and infrared spectroscopy. In the case of annealing in the range of 600-800 • C, anatase and rutile phases coexist. Disorder-induced gap state (DIGS) density is greater for 700 • C annealed HPRS films than for 750 • C annealed ALD TiO 2 films, whereas 800 • C annealing offers DIGS density values similar to ALD cases. For ALD films, the studies clearly reveal the dependence of trap densities on the chemical route used.

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“…There is a large amount of uncertainty concerning the value of electron effective mass in TiO 2 obtained experimentally (typically, they are obtained from the analysis of Hall coefficients, conductivity and thermoelectric power): values for rutile have been reported in the range between 5 m e and 13 m e [79] [80] [81] [82] and as large as 12-32 m e [83]; however, it has been argued that the measured value is the mass of a polaron, while the mass of a bare electron is smaller, of the order of 3 m e [80] or 6-7 m e [84]. For anatase nanoparticles, the measured values are much smaller, ~1 m e [85] or 0.71-1.26 m e [86] depending on particle size. DFT calculations show that electron effective mass in both rutile and anatase is strongly anisotropic, between 0.6-1.2 m e for rutile [87] [88] and 0.04-0.48 for anatase [88]; optical effective mass which takes into account all occupied states in the conduction band has been calculated as ~0.5 m e and ~4 m e (direction-dependent) for anatase [89].…”

Section: Choice Of the Model Parametersmentioning

confidence: 99%

Continuum and atomistic description of excess electrons in TiO₂

Maggio¹,

Martsinovich²,

Troisi³

2016

J. Phys.: Condens. Matter

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The modelling of an excess electron in a semiconductor in a prototypical dye sensitised solar cell is carried out using two complementary approaches: atomistic simulation of the TiO 2 nanoparticle surface is complemented by a dielectric continuum model of the solventsemiconductor interface. The two methods are employed to characterise the bound (excitonic) states formed by the interaction of the electron in the semiconductor with a positive charge opposite the interface. Density-functional theory calculations show that the excess electron in TiO 2 in the presence of a counterion is not fully localised but extends laterally over a large region, larger than system sizes accessible to DFT calculations. The numerical description of the excess electron at the semiconductor-electrolyte interface based on the continuum model shows that the exciton is also delocalised over a large area: the exciton radius can have the values from tens to hundreds of Ångströms, depending on the nature of the semiconductor (characterised by the dielectric constant and the electron effective mass in our model).

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On the non-linear I–V characteristics of dc magnetron sputtered TiO2 thin films

Cited by 37 publications

References 9 publications

A surface science perspective on TiO2 photocatalysis

A surface science perspective on TiO2 photocatalysis

A comparative study of the electrical properties of TiO₂films grown by high-pressure reactive sputtering and atomic layer deposition

Continuum and atomistic description of excess electrons in TiO₂

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On the non-linear I–V characteristics of dc magnetron sputtered TiO2 thin films

Cited by 37 publications

References 9 publications

A surface science perspective on TiO2 photocatalysis

A surface science perspective on TiO2 photocatalysis

A comparative study of the electrical properties of TiO2films grown by high-pressure reactive sputtering and atomic layer deposition

Continuum and atomistic description of excess electrons in TiO2

Contact Info

Product

Resources

About

A comparative study of the electrical properties of TiO₂films grown by high-pressure reactive sputtering and atomic layer deposition

Continuum and atomistic description of excess electrons in TiO₂