Electroluminescence in Single Crystals of Zinc Sulphide

Alfrey, G F; Taylor, James

doi:10.1088/0370-1301/68/10/310

Cited by 82 publications

(45 citation statements)

References 9 publications

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“…where 'B o ' and 'b' are parameters, which depend on temperature and frequency of alternating voltage, the material and other details of the construction of EL cell [29,30]. This behaviour indicates effectiveness of acceleration -collision mechanism along with formation of a barrier of Mott-Schottky type.…”

Section: Voltage and Frequency Dependence Of El Brightnessmentioning

confidence: 99%

Electroluminescence studies of chemically deposited (Zn-Cd)S:Cu,F films

Khare

Bhushan

2006

Cryst. Res. Technol.

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Electroluminescence (EL) emission has been observed under AC field excitation in chemically deposited (dipping technique) films of (Zn-Cd)S:Cu,F using substrates of conducting glass plates. Results of XRD, SEM, absorption spectra, transmission spectra, EL emission spectra, voltage, frequency and temperature dependence and brightness waves of EL brightness are presented and discussed. SEM studies show better growth condition in presence of F. X-ray diffraction studies show diffraction lines due to CdS and ZnS. Both the studies represent average particle sizes of the order of 1Å. Absorption studies show change in band gap due to increasing concentration of ZnS. The observed EL emission (blue-green region) may be due to Cu, F combination. Results of transmission spectra give band gap similar to those given by absorption spectra. From voltage dependence of EL brightness acceleration-collision mechanism is found to be effective. Frequency dependence of EL brightness shows first an increase in brightness in the lower frequency range followed by saturation at higher frequencies. Temperature dependence of EL emission shows a maximum at 40°C. Brightness waves consist of primary and secondary waves, which depend on voltage and frequency of excitation & the ambient temperature.

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Section: Voltage and Frequency Dependence Of El Brightnessmentioning

confidence: 99%

Electroluminescence studies of chemically deposited (Zn-Cd)S:Cu,F films

Khare

Bhushan

2006

Cryst. Res. Technol.

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“…The instantaneous value of luminance B1 can be given [9] by the formula: Solving the set of Eqs. (3), (4), (7), (8), (10), (11), (13) and (14), the time dependence of the luminances B1 and B. of the elements EL1 and EL2 were computed.…”

Section: Theoretical Considerationmentioning

confidence: 99%

Electroluminescent Display with Picture Storage

Porada¹,

Schabowska-Osiowska²

1998

Active and Passive Electronic Components

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“…We have then a + fl = 1 [2] and ano = Ffln~ [3] to maintain a steady-state condition with respect to ionization and subsequent recombination. We further define ~I, as the fraction of the total number of electrons, no + N~, which are in the particle bulk at the beginning of a voltage half-cycle, and which fraction returns to the high-field region = ne/(ne + Nt) = n,/N+ [4] The fraction ~ is of course proportional to the number of ionized recombination centers, which, as mentioned above, are localized in the high-field region = N § [5] where X is a capture cross section for these centers relative to trapping.…”

Section: Ne + N~ = N § [I]mentioning

confidence: 99%

The Mechanism and Efficiency of Electroluminescence in ZnS Phosphors

Morehead

1960

J. Electrochem. Soc.

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This work describes the application of a model of the electroluminescent process to the photon emission and power consumption of insulated electroluminescent phosphors as a function of voltage and frequency. The model represents an extension of one described earlier. The model leads to a convenient summary of such data and an increased understanding of their significance. An upper limit to the efficiency of impact electroluminescence in insulated particles is proposed on the basis of the implications of the model.One of the difficulties encountered in correlating data for electroluminescence in ZnS phosphors is that there does not exist an adequate model of the process. The lack of such a model makes impossible a convenient summary of the variation of brightness and power dissipation with voltage, frequency, and temperature. Comparisons of the properties of the electroluminescence of different phosphors are difficult to describe in meaningful terms and even more difficult to relate to differences in the fundamental properties of the phosphors. The purpose of this work is to present as complete an approach to an adequate model based on the collision excitation mechanism as is possible at present.This model, to be described in the following section, is consistent with the relevant experimental data reported in the literature (1-6) although not in entire agreement with their interpretation [cf. (2, 3)]. The major premise is that of delayed recombination, which, despite alternative suggestions (7) remains unambiguously demonstrated (1, 2, 6). Further, the model is a straightforward extension of work by the present writer (1) with some changes suggested by consideration of efficiency. It is similar in concept but more detailed and more accurate than one described by Lehmann (5). Finally, the model yields a phenomenological approach toward estimating maximum efficiencies that can be achieved with electroluminescence produced by impact ionization. The primary consideration is the relation between the way in which light emission and power consumption increase with voltage in insulated particles. A Model of the Electroluminescence ProcessThe principal features of this model have been described previously (1); the same notation will be retained. The electrons participating in the electroluminescence process in a given particle are divided into two populations: no "mobile" electrons, which emerge from and return to a "high-field region" in each voltage cycle and N~ "trapped" electrons in the particle bulk which do not succeed in returning to 1Present address: Research Laboratory, International Business Machines Corp., Poughkeepsie, N. Y. this region. The origin of the high-field region in which carrier acceleration and impact ionization occur is discussed in a following section. It is assumed that all of the participating electrons have been ionized from the lattice and that the resultant holes are localized in the high-field region at N § recombination centers, so that ne + N~ = N § [i]Of the ne mobile electrons a fraction...

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Electroluminescence in Single Crystals of Zinc Sulphide

Cited by 82 publications

References 9 publications

Electroluminescence studies of chemically deposited (Zn-Cd)S:Cu,F films

Electroluminescence studies of chemically deposited (Zn-Cd)S:Cu,F films

Electroluminescent Display with Picture Storage

The Mechanism and Efficiency of Electroluminescence in ZnS Phosphors

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