scholarly journals On the dependence of the photoelectric current on the position of the plane of polarization of the exciting light in reference to the surface of the kathode

Author(s):  
J. Elster ◽  
H. Geitel
2020 ◽  
Vol 86 (9) ◽  
pp. 3-13
Author(s):  
Sergii Smola ◽  
Yevhen Fadieiev ◽  
Nataliia Rusakova ◽  
Mariya Rusakova ◽  
Ninel Efryushina

SiO2-Al2O3 xerogels with various Si : Al ratios were synthesized via sol-gel method (two kinds of synthetic procedures were used) and characterized by means of elemental analysis, XRD, thermogravimetry and IR spectroscopy. No losses of precursors were found during the synthesis and the introduced components are quantitatively transferred from the initial mixture to the composition of the formed samples.The position of the luminescence band in the 300–500 nm region depends on the wavelength of the exciting light, time of gel maturation and the drying temperature, which is the manifestation of the influence of the structure of units in xerogels on the luminescent properties.


2020 ◽  
Vol 128 (8) ◽  
pp. 1100
Author(s):  
А.В. Тюрин ◽  
С.А. Жуков ◽  
А.Ю. Ахмеров

It was previously found that in emulsion microcrystals (EMC) AgBr (I) (with silver content corresponding to pBr 4), the centers responsible for tunneling recombination at T = 77 K, with a maximum of luminescence at λmax~ 560 nm when excited from light from the absorption region of AgBr (I) EMCs (λ ~ 450 nm) as a result of temperature quenching, they undergo structural transformation into centers, which, under the same excitation, provide tunneling recombination with a wavelength depending on the binder: for EMC AgBr (I) obtained in water ‒ λmax~ 720 nm, in gelatin ‒ λmax~ 750 nm. In the present work, similar structural transformations of the centers determining tunneling recombination with λmax~ 560 nm, to the centers with luminescence on λmax~ 720 nm were implemented for AgBr (I) EMCs synthesized in polyvinyl alcohol (PVA) with an increase in the content of silver ions in the emulsion (from pBr 4 to 7). Responsible for this transformation, as follows from the obtained results, are mobile interstitial silver ions Agi +, which transform these tunnel recombination centers. The effect of the binder on the recombination processes in EMC AgBr (I) is manifested in changes in the kinetics of the increase in luminescence with λmax~ 560 nm upon excitation by light from the absorption region of AgBr (I) EMC (λ ~ 450 nm) to a stationary level. For a binder whose molecules do not interact with Ag centers Agin+, n = 1, 2 (water, PVA at pBr 4), increase in luminescence with λmax~ 560 nm occurs monotonically from zero to the maximum stationary level. For a binder (in our case, G is gelatin), whose molecules with centers Agin+ (n = 1,2) form complexes (Agin0G+), the kinetics of the increase in luminescence in EMC AgBr (I) to a stationary level at λmax~ 560 nm at pBr 4 is characterized by the presence of “flash flare”. Adsorption on the surface of EMC AgBr (I) (in PVA at pBr 7) of the dye is manifested as follows: if, before the introduction of the dye, the kinetics of the increase in luminescence with λmax~ 560 nm, when excited from light from the absorption region of AgBr (I) EMC (λ ~ 450 nm) to a stationary level, “flare-up” appeared, then after the introduction of the dye, the luminescence increases with λmax~ 560 nm occurs monotonically from zero to the maximum stationary level. Studies of the “flash” of luminescence stimulated by infrared (IR) light, after the termination of the action of exciting light, showed that when the kinetics of the increase in luminescence with λmax~ 560 nm to the stationary level, it exhibits "flare-up", a "flash" stimulated by IR light is not observed at λ ~ 560 nm. In the absence of “flash flare”, a “flash” at λ ~ 560 nm is observed. From our point of view, the results obtained indicate that “flare-up burning” is due to the presence of deep centers of electron localization with a small capture cross section, and not a photochemical reaction stimulated by exciting light. Key words: AgBr (I) microcrystals, emulsions, glow centers, luminescence flare-up.


2017 ◽  
Vol 64 (5) ◽  
pp. 2257-2260 ◽  
Author(s):  
Yao Xiao ◽  
Ting-Zhu Wu ◽  
Si-Jia Dang ◽  
Yu-Lin Gao ◽  
Yue Lin ◽  
...  

1984 ◽  
Vol 38 (1) ◽  
pp. 78-83 ◽  
Author(s):  
R. Thurn ◽  
W. Kiefer

We report on a new Raman microprobe technique where micron-sized solid particles are trapped in stable optical potential wells using only the force of radiation pressure from a continuous gas laser. We demonstrate this technique with Raman spectra from spherical and non-spherical particles of sizes ranging between 10–30 μm. The particles are stably supported by a vertical directed focused TEM00-mode cw argon ion laser of ∼500 mW. The latter simultaneously serves as the exciting light source. Several suggestions for improvements of this technique are made.


2006 ◽  
Vol 33 (1) ◽  
pp. 9 ◽  
Author(s):  
Dušan Lazár

Chlorophyll a fluorescence rise caused by illumination of photosynthetic samples by high intensity of exciting light, the O–J–I–P (O–I1–I2–P) transient, is reviewed here. First, basic information about chlorophyll a fluorescence is given, followed by a description of instrumental set-ups, nomenclature of the transient, and samples used for the measurements. The review mainly focuses on the explanation of particular steps of the transient based on experimental and theoretical results, published since a last review on chlorophyll a fluorescence induction [Lazár D (1999) Biochimica et Biophysica Acta 1412, 1–28]. In addition to ‘old’ concepts (e.g. changes in redox states of electron acceptors of photosystem II (PSII), effect of the donor side of PSII, fluorescence quenching by oxidised plastoquinone pool), ‘new’ approaches (e.g. electric voltage across thylakoid membranes, electron transport through the inactive branch in PSII, recombinations between PSII electron acceptors and donors, electron transport reactions after PSII, light gradient within the sample) are reviewed. The K-step, usually detected after a high-temperature stress, and other steps appearing in the transient (the H and G steps) are also discussed. Finally, some applications of the transient are also mentioned.


2015 ◽  
Vol 23 (4) ◽  
Author(s):  
T. Piotrowski ◽  
M. Węgrzecki ◽  
M. Stolarski ◽  
T. Krajewski

AbstractOne of the key parameters determining detection properties of silicon PIN detector structures (pThe paper presents a method for measuring the spatial distribution of effective carrier diffusion length in silicon detector structures, based on the measurement of photoelectric current of a non-polarised structure illuminated (spot diameter of 250 μm) with monochromatic radiation of two wavelengths λ


2014 ◽  
Vol 7 (2) ◽  
pp. 267-273
Author(s):  
苏彦勋 SU Yen-hsun ◽  
柯沅锋 KE Yuan-feng ◽  
蔡士良 CAI Shi-liang ◽  
姚芊瑜 YAO Qian-yu ◽  
徐嘉妘 XYU Jia-yun ◽  
...  

2013 ◽  
Vol 34 (2) ◽  
pp. 240-244
Author(s):  
杨振岭 YANG Zhen-ling ◽  
方伟 FANG Wei ◽  
杨延强 YANG Yan-qiang

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