Preparation of reflective CsI photocathodes with reproducible high quantum efficiency

Maier-Komor, P.; Bauer, B.; Friese, J.; Gernhäuser, R.; Kienle, P.; Körner, H. J.; Montermann, G; Zeitelhack, K.

doi:10.1016/0168-9002(95)00314-2

Cited by 22 publications

(7 citation statements)

References 11 publications

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“…Two strong absorption peaks are observed in the UV wavelength region at a wavelength smaller than 225 nm for thinner CsI films. A similar optical absorbance results for thinner and thicker CsI films are reported in previous literatures [8,9,10].…”

Section: Optical Absorbancesupporting

confidence: 90%

Optical and structural properties of CsI thin film photocathode

Pandit

Rai

Singh

2015

Nuclear Instruments and Methods in Physics Research Section A:

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In the present work, the performance of a cesium iodide thin film photocathode is studied in detail. The optical absorbance of cesium iodide films has been analyzed in the spectral range from 190 nm to 900 nm. The optical band gap energy of 500 nm thick cesium iodide film is calculated from the absorbance data using Tauc plot. The refractive index is estimated from envelope plot of transmittance data using Swanepoel's method. The absolute quantum efficiency measurement has been carried out in the wavelength range from 150 nm to 200 nm. The crystallographic nature and surface morphology are investigated by X-ray diffraction and transmission electron microscopy techniques. In addition, the elemental composition result obtained by energy dispersive X-ray analysis is also reported in the present work.

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Section: Optical Absorbancesupporting

confidence: 90%

Optical and structural properties of CsI thin film photocathode

Pandit

Rai

Singh

2015

Nuclear Instruments and Methods in Physics Research Section A:

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“…The optical absorption of reflective and semitransparent CsI thin films has been obtained by C. Lu et al [16], P. Maier et al [37], T. Boutboul et al [38] and Triloki et al [15]. We found that our results are having good match with them.…”

Section: Optical Properties Of Csi Thin Filmssupporting

confidence: 85%

Structural and optical properties of CsI thin films: Influence of film thickness and humidity

Jammal

Rai

Pandit

et al. 2018

Physica B: Condensed Matter

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Structural and optical studies have been performed on the thermally-evaporated "as-deposited" and "humid air aged" CsI thin films. The structural analysis for both "as-deposited" and "humid air aged" films shows a well-oriented peaks position of (110) and (220) lattice planes with a compressive stress in the films. The crystal quality has been investigated through the structural parameters. The increase in peak intensity as well as sharpness with film thickness implies the improvement of crystallinity. The optical absorbance of CsI films has been analyzed in the wavelength range of 190 nm -900 nm in order to estimate the band gap energy of the films. Slater's model has also been used to explain the degradation of band gap energy with the increase in crystallite size. been tested successfully under liquid xenon atmosphere for its use in dark matter search experiment [21]. The detectors used for these experiments generally work in two modes; reflective (opaque) and semitransparent mode. The Quantum Yield (QY) of reflective films has been observed to be higher in comparison with the semitransparent films. This is because the semitransparent films have a small escape length (L≤ 10 nm) [16]. Also, it has been revealed that the reflective films have more chemical stability against the moisture compared to the semitransparent films [17].Keeping these facts in mind, the main issue related to CsI photocathode is the aging which causes a degradation in the photoemission properties and thus limits their life. In order to develop and optimize large area photocathodes based detector, the study of the optical and structural properties of the "as-deposited" and "aged" CsI photocathodes is ultimately required. In literature, there are several studies on CsI ageing, but its mechanism does not have a clear understanding yet. A. S. Tremsin et al. [23] have used TEM technique to study the structural properties of polycrystalline CsI thin film of 100 nm thickness under the impact of humid air and UV irradiation. M. A. Nitti et al. [24] have examined the bulk structure and the surface of freshly and humid air exposed 100 nm CsI film by XRD and XPS measurements. Recently, Triloki et al. [25] have studied the structural properties of thermally-evaporated CsI thin films of different thicknesses by using XRD and TEM techniques. C. Lu and K.T. McDonald [16] have previously reported the optical properties of freshly CsI thin films up to 31 nm thickness. This work is an extension of the previous works, where we have systematically studied the structural and optical properties of semitransparent and reflective CsI thin films grown under similar vacuum-environment in case of "as-deposited" and "humid air aged". Experimental Details Deposition of CsI thin filmsThe deposition of reflective (500 nm and 300 nm) and semitransparent (50 nm and 30 nm) CsI thin films was done in a stainless steel 18" diameter spherical vacuum chamber. Prior to the deposition process, the substrates were cleaned by treating with distilled water, acetone, and alcohol to...

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“…Even two orders of magnitude reduction in turn-on voltage was successfully achieved by means of CsI coating on carbon fiber-based FE devices by the same group [14]. Due to the importance of CsI photocathodes, several thin film preparation methods, such as thermal evaporation [15,16], ion beam sputtering [17], e-gun evaporation [18], spray pyrolysis [19], pulsed laser deposition [20] are used to study the various physical and chemical properties of CsI. However, it has been observed that the thermal evaporation is the best choice forming a stoichiometric Cs:I ratio [21] as well as the highest absolute quantum efficiency (QE) compared to other preparation techniques [17][18][19][20].…”

Section: Introductionmentioning

confidence: 99%