A multiple-trapping model with optical bias

Pandya, R.; Schiff, E. A.

doi:10.1080/13642818508238952

Cited by 41 publications

(10 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the relatively low power range, the photocurrent is low partly because of the more important contribution of trap recombination. Trap lling can enhance the lifetime of the photogenerated charge carriers and can improve the quantum yield at higher light intensities, [47][48][49] With increased intensity, the traps can be saturated, leading to enhanced photocurrent. Therefore, we think that the relatively low IPCE values should be attribute to trap lling effect due to weaker light intensity at IPCE measurements.…”

Section: Resultsmentioning

confidence: 99%

Enhancing visible-light photoelectrochemical water splitting through transition-metal doped TiO₂ nanorod arrays

et al. 2014

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 99%

Enhancing visible-light photoelectrochemical water splitting through transition-metal doped TiO₂ nanorod arrays

et al. 2014

View full text Add to dashboard Cite

show abstract

“…To gain insight into the transport mechanism, we examine the adequacy of the classical diffusion model 5 (eqs C.3 and C.4) to describe electron transport in the film as a function of the illumination geometry and the wavelength of the probe light. Figure displays the IMPS responses of a cell, corresponding to the Fourier transform of the current transients in Figure …”

Section: Resultsmentioning

confidence: 99%

Nonthermalized Electron Transport in Dye-Sensitized Nanocrystalline TiO₂ Films: Transient Photocurrent and Random-Walk Modeling Studies

2001

View full text Add to dashboard Cite

A random-walk approach is developed to model the electron-transport dynamics in dye-sensitized TiO2 solar cells within a multiple-trapping framework, and the predicted results are compared with those measured by transient photocurrent. The illumination geometry and the wavelength of the probe light are used to create certain initial spatial distributions of photoinjected electrons in the TiO2 films. Both have a dramatic effect on the shape of the measured photocurrent transient. Cells are probed with light incident from either the collecting (substrate) electrode side or the counter-electrode side. Excellent correspondence between simulated and measured current transients is observed. When electrons are injected far from the collecting electrode, their diffusion is found to be classical, corresponding to thermalized (nondispersive) transport. Nonthermalized (dispersive) electron transport is shown to be important when electrons are injected near the collecting electrode, which corresponds to the illumination condition under which the cell normally operates. For strongly absorbed light incident from the collecting electrode side, it is estimated that about 80% of injected electrons are collected before they are within 95% of complete thermalization. Failure to account for the presence of nonthermalized electrons is shown to be a major limitation of previous theories of electron transport. The total density of trap states is estimated to be relatively small, on the order of 1 trap per particle. The average detrapping time is on the order of 10 ns. When electrons are generated far from the collecting electrode, they undergo an average of about 106 trapping events before being collected. Analytical expressions are derived that relate the experimentally measured collection time to other parameters affecting transport (e.g., trap density, light intensity, film thickness, and free-electron mobility). Experimental evidence is presented for ambipolar diffusion.

show abstract

“…2b). Systematical studies of the optical bias effect on transient photocurrent in amorphous semiconductors have been interpreted in on the basis of population of the deep traps [8]. In "time-of-flight" experiments in amorphous As 2 Se 3 :Sn films it was also shown that the "optical bias" increase the drift mobility and decrease the recombination time [9].…”

Section: Resultsmentioning

confidence: 98%

“…According to 119 Sn in the As 2 Se 3 :Sn glassy system according th the Mössbauer spectroscopy [8], new tetrahedral Sn(Se 1/2 ) 4 and quasi-octahedral SnSe structural units can be formed, and which can influence the photostructural transformations. For the Sb 2 Se 3 :Sn, in dependence of the composition of the amorphous thin films the "photodarkening" and "photobleaching" effects were established.…”

Section: Discussionmentioning

confidence: 99%

“…Special interest for the applications of chalcogenide amorphous films is connected with doping with metal impurities, which alter optical, photoelectrical and transport properties of the host material [4]. At the same time it was shown that doping of chalcogenide films by tin impurities assist in stabilizing the glassy matrix with respect to light exposure and thermal treatment [7,8]. According to Mössbauer spectroscopy of 119 Sn in the As 2 Se 3 :Sn glassy system according the, new tetrahedral Sn(Se 1/2 ) 4 and quasi-octahedral SnSe structural units can be formed, and which can influence the photostructural transformations [5].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Optical absorption and photoconductivity of As 2 Se 3 :Sn AND Sb 2 Se 3 :Sn thin film structures

Iovu¹,

Vasiliev²,

Harea³

et al. 2009

Advanced Topics in Optoelectronics, Microelectronics, and Nanotechnologies IV

View full text Add to dashboard Cite

The optical and photoelectrical characteristics of amorphous As 2 Se 3 :Sn and Sb 2 Se 3 :Sn prepared by vacuum evaporation on glass substrates are investigated. From the transmission spectra the changes of the refractive index under the light irradiation and heat treatment are calculated. The band gap for amorphous Sb 2 Se 3 was found to be E g =1.30 eV and decrease with increasing of the tin concentration up to E g =1.0 eV for Sb 2 Se 3 :Sn 10.0 . The kinetics of photoinduced absorption in the investigated thin films was studied. The relaxation of the photocurrent has been recorded in the wide times scale (from 0.05 up to 25 s) and was determined by capture on the deep acceptor-like traps. The photoconductivity spectra of amorphous Sb 2 Se 3 and Sb 2 Se 3 :Sn films in the photon energy range 1.0÷2.5 eV show the band connected with the presence of the defect states with the maximum located at 1.46 eV. The intensity of this band increases in the samples with tin impurity. The experimental data are discussed in framework of the model of the charged defects and nonequilibrium dielectric polarization in amorphous semiconductors.

show abstract

A multiple-trapping model with optical bias

Cited by 41 publications

References 28 publications

Enhancing visible-light photoelectrochemical water splitting through transition-metal doped TiO₂ nanorod arrays

Enhancing visible-light photoelectrochemical water splitting through transition-metal doped TiO₂ nanorod arrays

Nonthermalized Electron Transport in Dye-Sensitized Nanocrystalline TiO₂ Films: Transient Photocurrent and Random-Walk Modeling Studies

Optical absorption and photoconductivity of As 2 Se 3 :Sn AND Sb 2 Se 3 :Sn thin film structures

Contact Info

Product

Resources

About

A multiple-trapping model with optical bias

Cited by 41 publications

References 28 publications

Enhancing visible-light photoelectrochemical water splitting through transition-metal doped TiO2 nanorod arrays

Enhancing visible-light photoelectrochemical water splitting through transition-metal doped TiO2 nanorod arrays

Nonthermalized Electron Transport in Dye-Sensitized Nanocrystalline TiO2 Films: Transient Photocurrent and Random-Walk Modeling Studies

Optical absorption and photoconductivity of As 2 Se 3 :Sn AND Sb 2 Se 3 :Sn thin film structures

Contact Info

Product

Resources

About

Enhancing visible-light photoelectrochemical water splitting through transition-metal doped TiO₂ nanorod arrays

Enhancing visible-light photoelectrochemical water splitting through transition-metal doped TiO₂ nanorod arrays

Nonthermalized Electron Transport in Dye-Sensitized Nanocrystalline TiO₂ Films: Transient Photocurrent and Random-Walk Modeling Studies