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Charakterizace tenkovrstvých elektroluminiscenčních součástek
Ahmed, Mustafa M. Abdalla ; Hrabovský, Miroslav (oponent) ; Tománek, Pavel (vedoucí práce)
The objective of this thesis is to study the optical and electrical characterization of Alternating-Current Thin-Film ElectroLuminescent (ACTFEL) devices, and specifically the aging process of phosphor materials that comprise the ACTFEL display in an effort to improve the overall performance of the primary phosphor colors in terms of brightness, efficiency and stability. Since the dominant flat-panel display technology is the LCD, an alternative flat-panel display technology must gauge itself in terms of the LCD. The advantages of ACTFEL displays in comparison with LCDs are the ability to pattern much smaller pixel, performance over a wider temperature range, full-viewing angle, and readability with much greater intensity background light. The disadvantages of ACTFEL displays against LCD ones are larger power consumption, lack of adequate chromaticity of the three primary colors, and much larger driving voltages. To achieve these objectives, the optical, electrical, and opto-electric measurements of the ACTFEL structures and ZnS:Mn phosphor hosts were carried out. Moreover, the effect of KCl co-doping on the microstructure and the electroluminescent properties (mainly brightness and luminous efficiency) of ZnS:Mn phosphors has been investigated, too. A non-common electrical characterization of ACTFEL devices has also been provided. We also calculated charged center scattering rates, and simulated the electron transport process in an ACTFEL device The study of the aging characteristics of evaporated and atomic layer epitaxy ZnS:Mn phosphors has been undertaken by monitoring the luminance-voltage (L-V) internal charge-phosphor field (Q-Fp) and capacitance-voltage (C-V) electrical characteristics at in selected time intervals during aging. Short-term and long-term ACTFEL aging studies has been provided and an attempt to visualize locally the structure of phosphor with a subwavelenght resolution using Scanning near-field optical microscope (SNOM) has also been presented. The practical case of a green Zn2GeO4:Mn (2% Mn) ACTFEL device operated at 50 Hz was studied and a luminance stability by a measurement of luminance-voltage (L-V) and luminous efficiency-voltage (eta-V) characteristics has been evaluated. A non-negligible and indiscreptible task of this thesis was also its pedagogical aspect. Therefore, the presented text can be considered as a textbook suitable for our students in Libya.
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Charakterizace tenkovrstvých elektroluminiscenčních součástek
Ahmed, Mustafa M. Abdalla ; Hrabovský, Miroslav (oponent) ; Tománek, Pavel (vedoucí práce)
The objective of this thesis is to study the optical and electrical characterization of Alternating-Current Thin-Film ElectroLuminescent (ACTFEL) devices, and specifically the aging process of phosphor materials that comprise the ACTFEL display in an effort to improve the overall performance of the primary phosphor colors in terms of brightness, efficiency and stability. Since the dominant flat-panel display technology is the LCD, an alternative flat-panel display technology must gauge itself in terms of the LCD. The advantages of ACTFEL displays in comparison with LCDs are the ability to pattern much smaller pixel, performance over a wider temperature range, full-viewing angle, and readability with much greater intensity background light. The disadvantages of ACTFEL displays against LCD ones are larger power consumption, lack of adequate chromaticity of the three primary colors, and much larger driving voltages. To achieve these objectives, the optical, electrical, and opto-electric measurements of the ACTFEL structures and ZnS:Mn phosphor hosts were carried out. Moreover, the effect of KCl co-doping on the microstructure and the electroluminescent properties (mainly brightness and luminous efficiency) of ZnS:Mn phosphors has been investigated, too. A non-common electrical characterization of ACTFEL devices has also been provided. We also calculated charged center scattering rates, and simulated the electron transport process in an ACTFEL device The study of the aging characteristics of evaporated and atomic layer epitaxy ZnS:Mn phosphors has been undertaken by monitoring the luminance-voltage (L-V) internal charge-phosphor field (Q-Fp) and capacitance-voltage (C-V) electrical characteristics at in selected time intervals during aging. Short-term and long-term ACTFEL aging studies has been provided and an attempt to visualize locally the structure of phosphor with a subwavelenght resolution using Scanning near-field optical microscope (SNOM) has also been presented. The practical case of a green Zn2GeO4:Mn (2% Mn) ACTFEL device operated at 50 Hz was studied and a luminance stability by a measurement of luminance-voltage (L-V) and luminous efficiency-voltage (eta-V) characteristics has been evaluated. A non-negligible and indiscreptible task of this thesis was also its pedagogical aspect. Therefore, the presented text can be considered as a textbook suitable for our students in Libya.
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