High quantum efficiency transmission-mode GaAlAs photocathode with a nanoscale surface structure
TLDR
In this paper, a photocathode with a graded Al composition structure was designed, in which the Al composition of the emission layer is decreased gradually from bulk to surface, and the outermost layer is GaAs.Abstract:
To obtain a high quantum efficiency transmission-mode GaAlAs photocathode, a photocathode with a graded Al composition structure is designed, in which the Al composition of the emission layer is decreased gradually from bulk to surface, and the outermost layer is GaAs. Based on the graded Al composition structure, GaAlAs photocathodes with different thicknesses of GaAs layers are prepared. The experimental results show that the quantum efficiency of the GaAlAs photocathode in blue-green light significantly increased when the thickness of the outermost GaAs achieves a dozen nanometers. The peak quantum efficiency of a GaAlAs photocathode with a nanoscale GaAs layer could achieve 31%, which appears at 620 nm. The nanoscale surface structure has a quantum confinement effect, which is the main factor in the increased quantum efficiency of the GaAlAs photocathode.read more
Citations
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Pre-Emission Study of Photoelectron Dynamics in a GaAs/AlGaAs Photocathode
TL;DR: In this article, a pump-probe transient reflectometry was used to evaluate the transient evolution of photoelectron population near the device surface, which provided a direct picture of electron diffusion and decay.
Journal ArticleDOI
Photoelectron Transportation Dynamics in GaAs Photocathodes
TL;DR: In this article, a general theory describing photoelectron transportation dynamics in GaAs semiconductor photocathodes is presented, where gradient doping is incorporated in the model through the inclusion of directional carrier drift, leading to the characterization of key device parameters such as diffusion constant and electron decay rates.
Journal ArticleDOI
Photoelectron transportation dynamics in GaAs photocathodes
TL;DR: In this article, a general theory describing photoelectron transportation dynamics in GaAs semiconductor photocathodes is presented, where gradient doping is incorporated into the model through the inclusion of directional carrier drift.
Proceedings ArticleDOI
Pump-probe study of ultrafast response of GaAs photocathodes grown by MOCVD and MBE
TL;DR: In this article, a femtosecond pump-probe reflectometry (PPR) was used to measure the transient reflectivity of two gradient-doped GaAs photocathodes fabricated using two different methods, viz. molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD).
References
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Journal ArticleDOI
Electron–electron and electron‐hole interactions in small semiconductor crystallites: The size dependence of the lowest excited electronic state
TL;DR: In this paper, the excited electronic states of semiconductor crystallites sufficiently small (∼50 A diam) that the electronic properties differ from those of bulk materials were modeled, and an approximate formula was given for the lowest excited electronic state energy.
Journal ArticleDOI
GaAs, AlAs, and AlxGa1−xAs: Material parameters for use in research and device applications
TL;DR: In this article, a review of the properties of the Al x Ga1−x As/GaAs heterostructure system is presented, which can be classified into sixteen groups: (1) lattice constant and crystal density, (2) melting point, (3) thermal expansion coefficient, (4), lattice dynamic properties, (5) lattices thermal properties,(6) electronic-band structure, (7) external perturbation effects on the bandgap energy, (8) effective mass, (9) deformation potential, (10) static and
Journal ArticleDOI
Photoelectron surface escape probability of (Ga,In)As : Cs–O in the 0.9 to [inverted lazy s] 1.6 μm range
TL;DR: In this paper, the surface escape probability of Ga1−xInxAs alloys in the composition range 0≤x≥0.52 and band gap (Eg) range of 1.38 to 0.74 eV were investigated with Cs and O2.
Journal ArticleDOI
Photoemission study of Cs–NF3 activated GaAs(100) negative electron affinity photocathodes
TL;DR: In this article, the activation layers of negative electron affinity photocathodes were investigated using synchrotron radiation photoelectron spectroscopy (SR-PES) at photon energies ranging from 70eV to 820eV.
Journal ArticleDOI
Photocathodes for the energy recovery linacs
Triveni Rao,Andrew Burrill,Xiangyun Chang,John Smedley,Tomohiro Nishitani,C. Hernandez Garcia,M. Poelker,E.A. Seddon,F.E. Hannon,Charles Sinclair,John W. Lewellen,Donald W. Feldman +11 more
TL;DR: In this paper, an overview of existing and emerging technologies on electron sources that can service various energy recovering linacs under consideration Photocathodes that can deliver average currents from 1 mA to 1 A, the pros and cons associated with these cathodes are addressed status of emerging technologies such as secondary emitters, cesiated dispenser cathodes, field and photon assisted field emitters and super lattice photocathodes are also reviewed.