Photoelectrochemical measurement of effective diffusion length of carriers in lamellar semiconductors. Application to InSe

Theys, B.

doi:10.1051/rphysap:019880023080137500

Cited by 3 publications

(2 citation statements)

References 20 publications

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“…A step‐function initial condition is established as

n_{j} true(z, 0 true) = true{\begin{array}{c} center & N_{0, G a A s} & z = 0 \\ center & \frac{N_{0, I n S e} {normale}^{(- α (L_{j} - z))}}{L_{j}} & z > 0 \end{array}

where

N_{0, G a A s}

and

N_{0, I n S e}

are initial carrier density in the GaAs material and InSe at t = 0 just after light pump pulse, respectively.

α

is the linear InSe absorption coefficient at 800 nm wavelength parallel to the c ‐axis (

α = \approx 1800 {cm}^{- 1}

) . L j ( j : thick, medium, thin) are the three thicknesses studied mentioned above.…”

Section: Theorymentioning

confidence: 99%

“…Layered semiconductors or van der Waals solids as, for example, 2D γ‐InSe phase, have two channels for carrier transport, the so‐called vertical transport/interplanar transport between layers of material and the horizontal/intraplanar transport. The latter is usually found 10–1000 times faster channel for carrier transport than interplanar transport . Although experimental techniques accounting few layers of bulk InSe have demonstrated a slower intraplanar diffusion .…”

Section: Introductionmentioning

confidence: 99%

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Determination of Carrier Diffusion Length Using Transient Electron Photoemission Microscopy in the GaAs/InSe Heterojunction

Juárez-Pérez

2019

Physica Status Solidi (b)

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Carrier diffusion length and lifetime parameters for electron transport at nanoscale semiconductor slabs have been fitted using a 1D model and the decay data extracted from transient photoemission electron microscopy. Meanwhile, a conventional photoluminescence quenching measurement needs two separate samples with an active material between blocking and quenching layers to characterize the carrier transport properties. In this work, only one few-layer monocrystalline sample of γ-InSe containing different thicknesses of active material is used to obtain a common diffusion coefficient consistent with previously reported values for vertical carrier diffusion in layered InSe.

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“…A step‐function initial condition is established as

n_{j} true(z, 0 true) = true{\begin{array}{c} center & N_{0, G a A s} & z = 0 \\ center & \frac{N_{0, I n S e} {normale}^{(- α (L_{j} - z))}}{L_{j}} & z > 0 \end{array}

where

N_{0, G a A s}

and

N_{0, I n S e}

are initial carrier density in the GaAs material and InSe at t = 0 just after light pump pulse, respectively.

α

is the linear InSe absorption coefficient at 800 nm wavelength parallel to the c ‐axis (

α = \approx 1800 {cm}^{- 1}

) . L j ( j : thick, medium, thin) are the three thicknesses studied mentioned above.…”

Section: Theorymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Determination of Carrier Diffusion Length Using Transient Electron Photoemission Microscopy in the GaAs/InSe Heterojunction

Juárez-Pérez

2019

Physica Status Solidi (b)

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Photovoltaic Properties of Solid State Junctions of Layered Semiconductors

Bücher

1992

Physics and Chemistry of Materials With Low-Dimensional Structures

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Laser spot scanning in photoelectrochemical systems, relation between spot size and spatial resolution of the photocurrent

Eriksson

Carlsson

Holmström

et al. 1991

Journal of Applied Physics

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Laser spot scanning studies of single-crystallinep-InSe in contact with a neutral aqueous solution reveal a dramatic difference in lateral resolution between the material "as cleaved" and after platinization by brief dipping in a dilute H,PtCl, solution. A model is developed to explain these observations, and the resolution is calculated as a function of the diffusion coefficient and the life time of minority carriers, and of the charge transfer rate. The improvement of the resolution is found to be due to the increase of the rate of hydrogen evolution at the illuminated semiconductor by Pt catalyst. The model also provides numerical values for the charge transfer rate in the noncatalyzed and the catalyzed cases. INTRODUCTlONDuring the last decade a new technique to study the photoelectrochemical (PEC) properties of semiconductor surfaces has been developed, utilizing a spot of highly focused laser light scanned across the surface.'-' This technique, known as laser spot scanning (LSS), has opened new possibilities for laterally resolved studies of the effects of illumination at semiconductor-liquid junctions.In this technique, a laser spot is scanned over the semiconductor surface and the photocurrent is recorded. Photocurrent images can be directly related to surface structures of polycrystalline materials, such as grain boundaries and surface defects, as shown for TiO, (Refs. 1 and 5) and for nSi.3 Studying the effect of surface treatments is greatly facilitated, as different treatments can be made on the same material and then directly examined with the LSS apparatus. The correlation of surface treatment or structural features of the surface with PEC properties has been studied with the LSS technique, for n = GaAs, n-WSe,,4 and for p-InSe.' PEC etching of pits on CdSe with focused laser light of high intensity might have applications in data storage.* We took a novel approach to the laser scanning microscopy by introducing fiber optics.7 We let the laser beam focus onto the end of a single mode glass fiber. The other end is fitted with a SelfocO lens that focuses the outcoming laser light to a small spot. This approach gives a simpler apparatus for the x/y scanning of the focused light spot across the semiconductor surface. Another benefit of this approach is evident in photoelectrochemical studies. The apparent light source (the end of the fiber) can be moved very close to the semiconductor surface and thus avoiding blurring of the image or damping of the light as the light passes through the electrolyte.The resolution of LSS is limited by the size of the focused spot of laser light; values down to a few microns are reported. IV3 However, we found that the spatial resolution was much lower than the spot size.In this paper we develop a model to simulate the spatial resolution as a function of properties of the semiconductor "'Authors to whom correspondence should be addressed. material (mobility and life time of minority carriers) and of the chemical system (rate of charge transfer from the semiconductor to t...

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Photoelectrochemical measurement of effective diffusion length of carriers in lamellar semiconductors. Application to InSe

Cited by 3 publications

References 20 publications

Determination of Carrier Diffusion Length Using Transient Electron Photoemission Microscopy in the GaAs/InSe Heterojunction

Determination of Carrier Diffusion Length Using Transient Electron Photoemission Microscopy in the GaAs/InSe Heterojunction

Photovoltaic Properties of Solid State Junctions of Layered Semiconductors

Laser spot scanning in photoelectrochemical systems, relation between spot size and spatial resolution of the photocurrent

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