Cadmium Sulfide Crystals Research Articles

Influence of Thermally Created Sulfur Vacancies on Sublimation of Cadmium Sulfide Crystals

Cadmium sulfide vapor pressure measured by means of the glass membrane manometer method is discussed. The {log10P, T-1} curve consists of two straight lines corresponding to the temperature ranges below and above a critical temperature Tc (=740 K). The sublimation enthalpy obtained from the straight line below Tc was 76.4 k·cal/mol, which agrees well with the enthalpy of sublimation of the well-known reaction, CdS(s)=Cd(g)+(1/2)S2(g). As for sublimation above Tc, it is concluded that, in addition to the said reaction, another reaction, CdS(s)=CdS1-x(s)+(x/2)S2(g), occurs which causes sublimation suppression, and that the activation energy necessary to create an excess of Cd (a sulfur vacancy) in a CdS crystal is 3.19 k·cal/mol or 0.138 eV.

Radiation from 4.5 GeV electrons in piezoelectric crystals

Experimental data on spectral distributions and integral yields of radiation from 4.5 GeV electrons in piezoelectric quartz, lithium niobate and cadmium sulphide crystals of different thicknesses under axial and planar channeling are reported.

The use of a multigigahertz digital oscilloscope as a full-wave microwave detector for subnanosecond time-resolved microwave conductivity measurements

A ‘‘6-GHz’’ transient digitizing oscilloscope (Tektronix 7250) has been used as a nonrectifying detector of microwaves in the X-band region (8.2–12.4 GHz) to observe subnanosecond transient changes in microwave power level transmitted by a crystal of cadmium sulfide when subjected to flash photolysis (25 ps, 532 nm) or pulse-radiolysis (300 ps, 3-MeV electrons). The response time for monitoring the change in microwave power level following the pulse was found to be approximately 200 ps.

Rearrangement of defects in single crystals of cadmium sulfide irradiated with fast electrons

This study exaines CdS single crystals subjected to a special nonalloying treatment, alloyed with copper, and annealed in a cadmium atmosphere. Irradiation of the test specimens by electrons with E ≈ 1.2 MeV led to the formation of mobile defects and to decomposition of the original donor-acceptor associates. Over time, the primary radiation defects form secondary defects which act as fast recombination centers responsible for impurity photoconductivity. New donor-acceptor pairs are formed when the irradiated specimens are stored, these pairs being paramagnetic centers. Conclusions are made as to the nature of the secondary radiation defects, which are distributed both in the body of the specimens and near their surface.

Hardening effect in Zn-doped cadmium sulphide crystals

The growth stability of sublimation-grown cadmium sulphide crystals was seen to increase when small amounts of Zn, on the order of about 10 19 atoms/cm 3, were added to it. Such behaviour has been attributed to a solution hardening effect.

Skeletal and hollow crystals of cadmium sulphide grown under time-increasing supersaturation

Abstract Growth morphologies of CdS crystals grown under time-increasing supersaturation conditions are described. The growth method is a closed-tube iodine vapour transport modification (LTVTP method, previously described), in which the growth temperature is kept constant while the source temperature is slowly increased with time. The supersaturation can thus be increased with the time increase of the source temperature. The crystals grown under small supersaturation conditions are found to be more perfect and not to exhibit skeletal and hollow forms, while these latter morphologies appear when the supersaturation is sufficiently high.

Effect of temperature and illumination on streamer discharges in cadmium sulfide and cadmium selenide single crystals

The excitation conditions, the orientation, the radiation spectra of streamer discharges and the effect of laser illumination and temperature on the properties of streamers in cadmium sulfide single crystals has appeared in previous studies. Light generation in CdSe single crystals and in the mixed compounds CdS/sub x/Se/sub 1-x/ was obtained with streamer excitation through detailed information on the crystallographic orientation of the streamers and radiation spectra of these crystals. In this paper, the authors present new data on the effect of the temperature and illumination in the region 77-520/sup 0/K on the probability of excitation and the orientation of streamer discharges in cadmium sulfide crystals; the characteristic features of excitation, orientation, and luminescence spectra of streamer discharges in CdS/sub x/Se/sub 1-x/. The crystals were illuminated with radiation from an incandescent lamp with controllable intensity in the spectral range 560-580 nm and by impulsive radiation from an LGT-21 nitrogen laser (wavelength = 337.1 nm and I/sub e/ = 30 kW/cm/sup 2/. The resistivity of the crystalline plates as a function of the illumination intensity was determined from measurements of the photoconductivity. The streamer illumination of the discharge was separated from the illumination background by interference light filters.

Determination of flat-band position of cadmium sulfide crystals, films, and powders by photocurrent and impedance techniques, photoredox reaction mediated by intragap states

Determination of flat-band position of cadmium sulfide crystals, films, and powders by photocurrent and impedance techniques, photoredox reaction mediated by intragap states

Time-resolved photoluminescence in the picosecond time domain from cadmium sulfide crystals immersed in electrolytes

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTime-resolved photoluminescence in the picosecond time domain from cadmium sulfide crystals immersed in electrolytesMoshe Evenor, Shimshon Gottesfeld, Zvi Harzion, Dan Huppert, and Stephen W. FeldbergCite this: J. Phys. Chem. 1984, 88, 25, 6213–6218Publication Date (Print):December 1, 1984Publication History Published online1 May 2002Published inissue 1 December 1984https://doi.org/10.1021/j150669a032RIGHTS & PERMISSIONSArticle Views226Altmetric-Citations32LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (714 KB) Get e-Alerts

Vector self-diffraction of light waves in cadmium sulfide crystals

Vector self-diffraction of light waves by polarization holograms was observed for the first time experimentally in CdS semiconductor crystals. These holograms were formed using the anisotropy of the fifth-order nonlinear susceptibility χ(5) related to the anisotropy of the two-photon absorption coefficient in the region of resonant contribution of the exciton states. The experimental results were interpreted allowing for the anisotropy of two-photon absorption.

Unique features of electrical conductivity in cadmium sulfide crystals irradiated by high-neutron dosages

Irradiation of semiconductors by high-energy heavy particles leads to the formation of defect clusters. The present study will analyze the dosage dependence of dark conductivity (σ) in high-resistance CdS single crystals upon irradiation by fast neutrons. Some parameters of defect clusters in the specimens studied are evaluated.

Laser annealing of cadmium sulfide crystals

Cadmium sulfide crystals with a disturbed surface layer about 5 μ thick were annealed by KrF* laser pulses of 10 nsec duration. This improved the crystal structure when the cadmium side was irradiated. The effect was not detectable on the sulfur side. The threshold energy density of the effect was ~0.25 J/cm2.

Response characteristics of a finite aperture, phase insensitive ultrasonic receiver based upon the acoustoelectric effect

The acoustoelectric effect (i.e., the interaction of ultrasound with conduction electrons in a piezoelectric semiconductor) provides the basis for the construction of a finite aperture, phase insensitive receiver using a single crystal of cadmium sulfide. In this paper we present a formalism describing the operation of such a receiver. Criteria for the optimization of the device in terms of ultrasonic bandwidth, response time, sensitivity, and electrical and mechanical loading are presented. In an accompanying paper [J. Acoust. Soc. Am. 70, 1377–1386 (1981)], we discuss and demonstrate the merits of using a phase insensitive receiver when measurements of a phase distorted (spatially noncoherent) ultrasonic radiation must be made.

Spectral and time dependences of the radiation emitted by cadmium sulfide crystals

A study was made of time and spectral-time characteristics of the radiation emitted from pure and doped cadmium sulfide subjected to high rates of excitation (1027 – 1028 cm−3sec−1) at 300 °K. The radiative transition times were determined for various recombination channels: τex = (11–12)×10−9 sec for the exciton mechanism accompanied by the emission of one or two phonons; τib = 6×10−9 sec for the interband mechanism (when the nonequilibrium carrier density was Δn = 1×1018 cm−3); τimp = (1–3)×10−9 sec for the mechanism involving shallow impurities. The interband radiative recombination coefficient Bib = 1.55×10−10 cm3/sec (Δn ~ 1018 cm−3), the critical density for the Mott transition ncr = 6.5 ×1017 cm−3, and the coefficient representing the binding of carriers into excitons γex ≈ 10−8 cm3/sec were determined.

Mechanisms of dynamic conversion of coherent optical beams in CdS

Theoretical and experimental investigations-were made of the process of energy transfer between two coherent beams during recording of a holographic grating in a cadmium sulfide crystal oriented in different directions with respect to the lines of the grating. It was shown that two mechanisms are responsible for the energy transfer: an electrooptic and a free-carrier mechanism. The type of carriers in the samples under study was determined from the direction of energy exchange.

Effect of high-temperature annealing in cadmium on the electrical transport properties of single crystals of cadmium sulphide

The effect of high-temperature annealing in cadmium on the electrical transport properties of n-CdS single crystals has been investigated. It has been found that the mobility values which were measured experimentally were lower than those calculated theoretically using a method based on the Brooks-Herring formula. The discrepancy has been mainly explained by applying the electron-electron scattering correction to the ionised-impurity scattering.

Scanning semiconductor laser with transverse electron-beam pumping

Stimulated emission was obtained from cadmium sulfide and sulfide-selenide crystals excited transversely by a sharply focused scanning electron beam at a frequency up to 16 kHz. The output power reached 1.2 W. A television image on a 1 m2 screen was obtained.

Analysis of the static method of the growth of cadmium sulphide crystals with large temperature gradients

AbstractThe paper gives an analysis of the thermodynamical conditions of crystallization of cadmium sulphide from the gaseous phase with the use of large temperature gradients in the course of crystal growth. From the achieved results there follows that large temperature gradients with the static method of crystal growth favourably influences the formation of crystallization nuclei and the growth of single crystals. The crystals cultivated under such conditions are comparatively large, their volume being several cm3 and their weight ranging from 40–60 g. These crystals are suitable for photoelectrical and electroacoustical measurements and various technical applications.

Formation and bleaching of optically-induced absorption bands in CdS:Cd, Cu crystals

Our earlier work has revealed the occurrence of three photoinduced bands in cadmium sulphide crystals appropriately doped with both cadmium and copper: one in the visible and two in the near IR region of the optical absorption spectrum. This investigation is now extended by examining the growth kinetics, their dependences on the temperature and on the excitation-light intensity, as well as the kinetics of thermal bleaching of the induced absorption. The data obtained are discussed in terms of the formation of photochemical complexes which give rise to the visible band. The IR bands are attributed to centers which are also responsible for the IR quenching of the photoconductivity.

The growth of cadmium sulphide from the vapour phase-surface kinetics

A model is proposed for the growth of cadmium sulphide crystals on the (11.2) face, and data on equilibrium partial pressures versus temperature are used to compute values of atomic binding energy and vibration frequency which are model dependent. These values are used to predict the temperature dependence of vacuum evaporation from the (00.1) faces of CdS, in order to establish their validity, and hence that of the model. It is found that consistent results are obtained provided evaporation is assumed to be limited by atoms in the “half crystal” energy state, and the implications of this for classical evaporation theory are discussed. In an earlier paper, the model of growth on the (11.2) surface proposed here was used to predict, with reasonable accuracy, the growth rate of crystals of this orientation as a function of the experimental conditions of growth.