&lt;title&gt;GaAsP photocathode with 40% QE at 550 nm&lt;/title&gt;

Edgecumbe, J.; Aebi, Verle W.; Davis, Gary A.

doi:10.1117/12.60336

Cited by 10 publications

(8 citation statements)

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“…T h e 3603 series are night-vision intensifiers and are not specifically designed for photon-counting. Improvements are clearly possible using a different method of image intensification: improved pulse-height distributions could be obtained using curved-channel or z-stacked M C P s operating in charge saturation mode (Slater et al 1990), and a GaAs photocathode could yield a much higher D Q E (Edgecumbe et al 1992).…”

Section: Discussionmentioning

confidence: 99%

The Sydney University PAPA Camera

Lawson¹

1994

Publ. Astron. Soc. Aust.

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The Papa camera is a photon-counting array detector that uses optical encoding to locate photon events on the output of a microchannel plate image intensifier. The Sydney University camera is a 256×256 pixel detector which can operate at speeds greater than 1 million photons per second and produce individual photon coordinates with a deadtime of only 300 ns. It uses a new Gray coded mask-plate which permits a simplified optical alignment and successfully guards against vignetting artifacts.

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Section: Discussionmentioning

confidence: 99%

The Sydney University PAPA Camera

Lawson¹

1994

Publ. Astron. Soc. Aust.

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“…GaAs1-xPx is a ternary Ⅲ-V compound semiconductor with the bandgap varying from 1.42eV (in GaAs) to 2.26eV (in GaP) [1] . In recent years, it has attracted wide attention in electronic devices, such as Light Emitting Diode (LED) [2,3] , photocathodes [4][5][6][7] , solar cells [8] , and so on. As we know, the blue-green light (450-570 nm) is an important way to communicate in the ocean, because the loss of the blue-green light transferring in the seawater is very low and the transmission efficient is high [9,10] .…”

Section: Introductionmentioning

confidence: 99%

“…As we know, the blue-green light (450-570 nm) is an important way to communicate in the ocean, because the loss of the blue-green light transferring in the seawater is very low and the transmission efficient is high [9,10] . To satisfy the need of ocean exploration, ocean communications, and under-sea imaging, GaAsP photocathodes with short cutoff wavelength and high quantum efficiency at blue-green light spectra were prepared by adjusting P component in GaAs photocathodes [4][5][6][7]. Jiao et al prepared a transmission-mode (t-mode) Al0.7Ga0.3As0.9P0.1/GaAs0.9P0.1 photocathode by molecular beam epitaxy(MBE), and the GaAsP sample possesses a quantum efficiency peak of 62% at 560 nm, and the quantum efficiency at 532nm is 59% [4] .…”

Section: Introductionmentioning

confidence: 99%

First principle research on Ga rich GaAs0.5P0.5(001) β2(4 × 2) and As(P) rich β2(2 × 4) reconstruction surfaces with and without Cs adsorption

Yang

Pei

2021

Opt Quant Electron

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Based on first principle calculations, Ga rich and As(P) rich clean GaAs0.5P0.5(001) reconstruction surfaces and adsorbed surfaces with 0.125ML coverage of Cs at different sites are researched. Formation energy of Ga rich GaAs0.5P0.5(001) β2(4×2) reconstruction surface is smaller than that of As(P) rich one, and the work functions of Ga rich β2(4×2) and As(P) rich β2(2×4) surfaces are 4.657 eV and 5.187 eV, respectively. The adsorption energies of Cs adatoms on both surfaces are negative, showing that Cs adsorption is a stable exothermic process. The work functions of two surfaces both decrease after Cs adsorption, and the average variation of As(P) rich β2(2×4) surface is larger. Mulliken charge analysis shows that Cs adatoms transfer electrons to GaAsP substrate, resulting in Cs-GaAsP dioples which lower the work functions. When Cs atoms are located at D2 of Ga rich surface and D2' of As(P) rich surface, work function values of the two reconstruction surfaces reach the minimums, which are 2.834eV and 2.859eV, respectively. By calculating dipole moments, it can be found that Cs adatoms on the topmost layer form larger effective dipole moments with GaAsP substrate than the Cs atoms located in the trench.

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“…In the last two decades, negative electron affinity (NEA) GaAsP-based photocathodes are of great technological interest and have found widespread application in various fields such as weak light imaging, high energy physics, astronomical observation and underwater photodetection. [1][2][3][4] As is well known, GaAsP-based photocathodes are divided into two basic types, i.e., reflection-mode (r-mode) cathodes for which the light is incident on the electron emission surface and transmission-mode (t-mode) cathodes for which the light is incident on the back surface.…”

Section: Introductionmentioning

confidence: 99%

“…As is well known, t-mode GaAsP-based cathode materials from Hamamatsu and Intevac are grown by metal-organic chemical vapor deposition (MOCVD) and vapor phase epitaxy (VPE). [1,13] In this paper, a type of t-mode GaAsP cathode material is tentatively fabricated by molecular beam epitaxy (MBE), and the packed 18-mm-diameter image intensifier including the activated GaAsP photocathode module is fabricated. In order to verify the actual effect of blue-green response enhancement, a blue-extended GaAs photocathode-based image intensifier as a comparison object is also fabricated.…”

Section: Introductionmentioning

confidence: 99%

Comparison of blue–green response between transmission-mode GaAsP- and GaAs-based photocathodes grown by molecular beam epitaxy

Jiao

Liu

Guo³

et al. 2016

Chinese Phys. B

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In order to develop the photodetector for effective blue-green response, the 18-mm-diameter vacuum image tube combined with the transmission-mode Al 0.7 Ga 0.3 As 0.9 P 0.1 /GaAs 0.9 P 0.1 photocathode grown by molecular beam epitaxy is tentatively fabricated. A comparison of photoelectric property, spectral characteristic and performance parameter between the transmission-mode GaAsP-based and blue-extended GaAs-based photocathodes shows that the GaAsP-based photocathode possesses better absorption and higher quantum efficiency in the blue-green waveband, combined with a larger surface electron escape probability. Especially, the quantum efficiency at 532 nm for the GaAsP-based photocathode achieves as high as 59%, nearly twice that for the blue-extended GaAs-based one, which would be more conducive to the underwater range-gated imaging based on laser illumination. Moreover, the simulation results show that the favorable blue-green response can be achieved by optimizing the emission-layer thickness in a range of 0.4 µm-0.6 µm.

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<title>GaAsP photocathode with 40% QE at 550 nm</title>

Cited by 10 publications

References 0 publications

The Sydney University PAPA Camera

The Sydney University PAPA Camera

First principle research on Ga rich GaAs0.5P0.5(001) β2(4 × 2) and As(P) rich β2(2 × 4) reconstruction surfaces with and without Cs adsorption

Comparison of blue–green response between transmission-mode GaAsP- and GaAs-based photocathodes grown by molecular beam epitaxy

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