In this research, we studied the phenomenon of energy transfer of polymer phosphorescent light-emitting diodes, PPLEDs. This thesis was divided into three parts: devices constructed by new-type host polymer blended with phosphorescent material, devices constructed by host polymer PVK blended with phosphorescent materials, and devices constructed by new-type phosphorescent polymer materials. The phenomenon of energy transfer between host polymer BP105 and phosphorescent dye Ir(ppy)3 was studied. Second, we chose PVK as a host polymer material, and Ir(ppy)3 as a phosphorescent guest material, to observe whether it can improve efficiency of devices by using energy transfer process. At last we manufactured devices constructed by new-type host polymer blended or bonded with new-type phosphorescent materials, and compared their emitting and energy transfer efficiency. A glycerol-modified PEDOT:PSS layer that used as an anode buffer layer in PLED using super yellow as the emitter was also been studied. It was found the glycerol-modified device showed a larger current density and improved luminescent efficiency then that of the unmodified device.

In this research,we used the electrochemical (cyclic voltammetry) method to synthesize (polyaniline) PANI thin film on the top of ITO substrate which applied extensively on polymer organic light emitting diodes based on ITO (170nm) / PANI (55nm ) / PFG(60 nm )/LiF(1nm)/Ca(10nm) / Al (200nm) . The PANI thin films have excellent optical and electric properties. According to the measurement results of ultraviolet visible spectrophotometry, the PANI thin films with different aniline monomer concentrations display the absorption peak at the range of 500nm to 600nm and have high light transmission near 90%. The conductivity of PANI thin film (2.02x10-2(s/cm)) is higher than that of PEDOT:PSS thin film (1.28x10-2(s/cm)). The highest occupied molecular orbital value of PANI thin film is about 5.0 eV that close to PEDOT:PSS thin film. Therefore, it is suitable act as hole transporting layer. In this study, we can control the surface morphology of PANI thin film by exchanging synthesized parameters. Finally, we have fabricated a PLED device with PANI as a hole transporting layer by electrochemical synthesis with at the aniline monomer concentration of 0.3M and the scan rate of 0.0.1 V/s. The device exhibits a maximum luminance of 10500 cd/m2 at 15 V and power efficiency of 0.25 lm/W at 10V.

Abstract Two novel conjugated polymers (PTP-SiO) and (PTP-P-SiO) with alternating N-containing heterocycles and siloxane (-Si-O-) units were synthesized using the Heck reaction. The incorporation of siloxane units in the polymers improves their thermal stability and processability. The polymers can be dissolved in organic solvent and exhibited good thermal stability with 5¢H weight loss temperature above 370¢J under nitrogen atmosphere. The photoluminescence (PL) spectra of PTP-SiO and PTP-P-SiO in solution show maximum peaks at 491 and 520 nm respectively. The heterocycles in the two polymers contain N- atoms, which can coordinate with transition or lanthanides metal ions to form complexes. The absorption spectra show peaks at around 275~290 nm and 320~330 nm, which are attributed to £k-£k* and n-£k* transitions, respectively. On the other hand, the emission spectra consist of peaks at around 408~420 nm and 491~520 nm. These two emission peaks belong to £k-£k* and n-£k* transitions of the ligands, respectively. With pyridazine ( heterocycle with ¡VN=N- group) ring, PTP-P-SiO shows more significant variation upon coordination with metals ions as compared to PTP-SiO. These variations of optical property offer a possibility for application in chemosensors for detection of metal ions.

Abstract This research focuses on the morphologies of polymers after the heat treatment, as the different temperature and time. To make a polymeric light emitting device (PLED), the wet procedure is used to composite the organic layer, such as spin coating, and has the very tremendous influence to its efficiency and performance. Thermal annealing plays an important role on it, especially the relationship between the glass transition temperature (Tg) and the boiling temperature of the solvent. In the experiment of wet procedure, we dissolved the green light polymer (PFG) into the chlorobenzene, and the Tg of PFG is about 108¢XC, and the solvent has been boiled at 134¢XC. After spin coating in the glove box, the organic layer became the liquid thin film, and we must bake it to the solid state. It took different morphologies of the polymers by changing the thermal temperature and time. And we can suppose the molecular arrangement from the ultraviolet-visible absorption spectrometry (UV-vis) and photoluminescence spectrometry (PL). Otherwise, we analyzed the surface morphology by using atomic force microscopy (AFM). Though the measurement of X-ray diffraction made the crystallinity of polymers discovered. After all, we prepared ITO(140nm) / PEDOT:PSS(65nm) /PFG(60nm)/ LiF(1nm) / Ca(10nm) / Al(200nm) for the PLED structure. According to the characteristic of the device, we can discuss what happen to the light emitting layer after thermal annealed. In the conclusion, we got the best performance when thermal temperature is nearby or above the Tg with the longer baking time. Respectively, the green light had the maximum luminance at 10.5v of 38710 cd/m2, and the current efficiency was 7.62 cd/A, and power efficiency was 2.66 lm/watt. And we have found higher baking temperature than Tg, as more than 135oC, made the worse performance through the longer time; except the 125oC. A transition thermal temperature, a little higher than Tg, made the performance keep stable after baking for a long time.

Utilizando a reação de acoplamento de Suzuki, novos polímeros e copolímeros semicondutores com elevado potencial para a fabricação de PLEDs foram sintetizados, tendo como finalidade unir em uma única camada emissiva, na forma de copolímeros ou na forma de blendas, materiais com propriedades transportadoras e injetoras de elétrons; grupos quinolina associados a materiais com elevadas propriedades de emissão de luz contendo grupos fluoreno. Esses copolímeros sintetizados, todos ainda não descritos na literatura ou em patentes, apresentaram rendimentos acima de 70% e rendimentos quânticos de fotoluminescência entre 60% e 83%, foram utilizados como camada emissiva na construção de PLEDs. Estes PLEDs foram caracterizados quanto ao seu comportamento elétrico através da obtenção de curvas de corrente em função da tensão (IxV) e dos espectros de eletroluminescência. Os resultados mostraram que a incorporação da quinolina aos copolímeros aumentou a sua estabilidade térmica, observada pela temperatura de inicio de degradação que elevou-se em até 80°C. Nos PLEDs, houve melhorias no balanceamento de cargas, dispensando até mesmo a deposição de uma camada adicional transportadora de elétrons (ETL). As tensões de operação desses dispositivos ficaram entre 2,0 e 5,2 V, com emissão entre 525 e 590nm. Esses materiais também tiveram as suas estruturas caracterizadas por ressonância magnética nuclear de hidrogênio, termogravimetria, calorimetria diferencial exploratória, espectroscopias no UV-Vis e no infravermelho, fluorimetria no UV-vis e cromatografia de permeação em gel. Filmes Langmuir e Langmuir- Blodgett dos copolímeros foram preparados e caracterizados por espectroscopia com luz polarizada de reflexão e absorção no infravermelho (PM-IRRAS) e por microscopia de força atômica (AFM). / New polymers and copolymers with a high potential for PLEDs constructions have been synthesized by Suzuki reaction and aims together in a single emissive layer in the form of copolymers or blended, materials with transporting and electron injection properties; quinoline groups linked to materials with high light emission properties as fluorene group. All these copolymers have not been described in literature or in patents, presented yields above 70%, quantum yields between 60% and 83% and were used as emissive layer in PLEDs. These PLEDs were characterized concerning their electrical behavior, by the characteristic J-V diode curves, and their electroluminescence. The results showed that the presence of quinoline increased its thermal stability at around 80° C and the PLEDs built with the synthesized copolymers do not need an extra ETL. The operating voltages of these devices were observed between 2.0 and 5.2 V with EL emission between 525 and 590nm. These new materials were also characterized by hydrogen nuclear magnetic resonance, thermogravimetry, differential scanning calorimetry, UV-Vis, Fluorescence and IR spectroscopy and gel permeation chromatography. Langmuir e Langmuir-Blodgett films were made and characterized by Polarization-Modulation Infrared Reflection-Absorption Spectroscopy (PM-IRRAS) and atomic force microscopy (AFM).

Utilizando a reação de acoplamento de Suzuki, novos polímeros e copolímeros semicondutores com elevado potencial para a fabricação de PLEDs foram sintetizados, tendo como finalidade unir em uma única camada emissiva, na forma de copolímeros ou na forma de blendas, materiais com propriedades transportadoras e injetoras de elétrons; grupos quinolina associados a materiais com elevadas propriedades de emissão de luz contendo grupos fluoreno. Esses copolímeros sintetizados, todos ainda não descritos na literatura ou em patentes, apresentaram rendimentos acima de 70% e rendimentos quânticos de fotoluminescência entre 60% e 83%, foram utilizados como camada emissiva na construção de PLEDs. Estes PLEDs foram caracterizados quanto ao seu comportamento elétrico através da obtenção de curvas de corrente em função da tensão (IxV) e dos espectros de eletroluminescência. Os resultados mostraram que a incorporação da quinolina aos copolímeros aumentou a sua estabilidade térmica, observada pela temperatura de inicio de degradação que elevou-se em até 80°C. Nos PLEDs, houve melhorias no balanceamento de cargas, dispensando até mesmo a deposição de uma camada adicional transportadora de elétrons (ETL). As tensões de operação desses dispositivos ficaram entre 2,0 e 5,2 V, com emissão entre 525 e 590nm. Esses materiais também tiveram as suas estruturas caracterizadas por ressonância magnética nuclear de hidrogênio, termogravimetria, calorimetria diferencial exploratória, espectroscopias no UV-Vis e no infravermelho, fluorimetria no UV-vis e cromatografia de permeação em gel. Filmes Langmuir e Langmuir- Blodgett dos copolímeros foram preparados e caracterizados por espectroscopia com luz polarizada de reflexão e absorção no infravermelho (PM-IRRAS) e por microscopia de força atômica (AFM). / New polymers and copolymers with a high potential for PLEDs constructions have been synthesized by Suzuki reaction and aims together in a single emissive layer in the form of copolymers or blended, materials with transporting and electron injection properties; quinoline groups linked to materials with high light emission properties as fluorene group. All these copolymers have not been described in literature or in patents, presented yields above 70%, quantum yields between 60% and 83% and were used as emissive layer in PLEDs. These PLEDs were characterized concerning their electrical behavior, by the characteristic J-V diode curves, and their electroluminescence. The results showed that the presence of quinoline increased its thermal stability at around 80° C and the PLEDs built with the synthesized copolymers do not need an extra ETL. The operating voltages of these devices were observed between 2.0 and 5.2 V with EL emission between 525 and 590nm. These new materials were also characterized by hydrogen nuclear magnetic resonance, thermogravimetry, differential scanning calorimetry, UV-Vis, Fluorescence and IR spectroscopy and gel permeation chromatography. Langmuir e Langmuir-Blodgett films were made and characterized by Polarization-Modulation Infrared Reflection-Absorption Spectroscopy (PM-IRRAS) and atomic force microscopy (AFM).

In this study, we investigated optoelectronic properties of white polymer light-emitting diodes. In the first part, we studied the energy transfer mechanism between the host material BP105 and the guest material RP119. By controlling the concentration of the dopant material, with the configuration of ITO/PEDOT:PSS/BP105:RP119/LiF/Al, we achieved the max luminance of 11580 cd/m2,luminance efficiency of 3.07cd/A with the CIE coordinate of (0.34, 0.36). In the second part, we added glycerol into HTL(Hole Transporting Layer) in order to enhance the conductivity. The structure of the device is ITO/glycerol:PEDOT:PSS/BP105:RP119(100:2)/LiF/Ca/Al, and the max luminance is 16040cd/m2, the luminance efficiency is 3.46cd/A,CIE coordinate is (0.34, 0.36). The luminance of the device with glycerol was 40% increased, the efficiency increased up to 13%. The CIE coordinate keep at (0.34, 0.36) between 9 and 14 voltage.

Os dispositivos emissores de luz orgânicos OLEDs têm despertado um enorme interesse tanto da comunidade científica quanto das empresas presentes no mercado mundial de displays. As características de elevado ângulo de visão, alta eficiência energética, possibilidade de confecção de displays flexíveis que não necessitam retroiluminação, baixo peso, fácil processabilidade, dentre outras, fazem com que os displays fabricados com materiais orgânicos apresentem um enorme potencial para as mais diversas aplicações. O presente trabalho teve como objetivo contribuir para a construção e caracterização de displays monocromáticos à base de polímeros luminescentes depositados pela técnica Ink Jet. Para tanto foram preparados os padrões de linhas x colunas, formadores dos pontos luminosos (pixels) de matrizes passivas e desenvolvidos processos para deposição dos filmes finos de polímeros semicondutores. A utilização da deposição por Ink Jet aparece como uma técnica chave para a produção de dispositivos poliméricos. Nesta pesquisa, como material luminescente foi utilizado um polímero da família do polifluoreno, de fácil processamento e elevada eficiência luminosa, enquanto que como eletrodos foram utilizados o óxido de estanho e índio (ITO) e Alumínio. O ITO foi utilizado por possuir baixa resistividade elétrica, elevada função de trabalho e elevada transmitância na região do visível. O processo de encapsulamento do display se deu por meio do acondicionamento destes dispositivos em ambiente isento de oxigênio e umidade, evitando-se os efeitos já conhecidos da foto-oxidação das camadas poliméricas. Os dispositivos, uma vez preparados, foram caracterizados por meio de medidas ópticas (fotoluminescência), elétricas (eletroluminescência, condutividade) e de desempenho (eficiência luminosa e luminância). / Organic Light Emitters Diodes OLEDs is a promising field of study and a huge market opportunity to semiconductor players. Thanks to its potential characteristics to replace the main todays display technologies like lightweight, low voltage, wide viewing angle, high resolution, fast switching, broad color range and the possibility to fabricate flexible devices, makes the organic semiconductors a potential candidate to develop, in a near future, devices and systems that even could not be imagined before. This work aims to contribute to the manufacturing process field and to the characterization of displays made by ink jet deposition technique. To achieve this objective, line x column patterns were produced, in which the pixels are generated at the crossing of lines and columns. The ink jet printing of materials is playing an important role in industry because it provides a low-cost manufacture environment potential. In this work, we studied the morphology of the ink jet deposition of polyfluorene over Indium Tin Oxide (ITO) substrates treated by different procedures. Those materials where used because the polyfluorene polymer presents high light emission efficiency and easiness of processing. The electrodes were prepared with ITO (due its low resistivity, high work function and high transmittance in the visible spectrum) and aluminum. The processed displays were sealed inside an inert ambient with positive pressure to avoid the photo-oxidation of the semiconductor luminescent polymer layers. The devices were characterized by optical (photoluminescence), electrical (electroluminescence) and performance (brightness, luminous efficiency) measurements.

Os dispositivos emissores de luz orgânicos OLEDs têm despertado um enorme interesse tanto da comunidade científica quanto das empresas presentes no mercado mundial de displays. As características de elevado ângulo de visão, alta eficiência energética, possibilidade de confecção de displays flexíveis que não necessitam retroiluminação, baixo peso, fácil processabilidade, dentre outras, fazem com que os displays fabricados com materiais orgânicos apresentem um enorme potencial para as mais diversas aplicações. O presente trabalho teve como objetivo contribuir para a construção e caracterização de displays monocromáticos à base de polímeros luminescentes depositados pela técnica Ink Jet. Para tanto foram preparados os padrões de linhas x colunas, formadores dos pontos luminosos (pixels) de matrizes passivas e desenvolvidos processos para deposição dos filmes finos de polímeros semicondutores. A utilização da deposição por Ink Jet aparece como uma técnica chave para a produção de dispositivos poliméricos. Nesta pesquisa, como material luminescente foi utilizado um polímero da família do polifluoreno, de fácil processamento e elevada eficiência luminosa, enquanto que como eletrodos foram utilizados o óxido de estanho e índio (ITO) e Alumínio. O ITO foi utilizado por possuir baixa resistividade elétrica, elevada função de trabalho e elevada transmitância na região do visível. O processo de encapsulamento do display se deu por meio do acondicionamento destes dispositivos em ambiente isento de oxigênio e umidade, evitando-se os efeitos já conhecidos da foto-oxidação das camadas poliméricas. Os dispositivos, uma vez preparados, foram caracterizados por meio de medidas ópticas (fotoluminescência), elétricas (eletroluminescência, condutividade) e de desempenho (eficiência luminosa e luminância). / Organic Light Emitters Diodes OLEDs is a promising field of study and a huge market opportunity to semiconductor players. Thanks to its potential characteristics to replace the main todays display technologies like lightweight, low voltage, wide viewing angle, high resolution, fast switching, broad color range and the possibility to fabricate flexible devices, makes the organic semiconductors a potential candidate to develop, in a near future, devices and systems that even could not be imagined before. This work aims to contribute to the manufacturing process field and to the characterization of displays made by ink jet deposition technique. To achieve this objective, line x column patterns were produced, in which the pixels are generated at the crossing of lines and columns. The ink jet printing of materials is playing an important role in industry because it provides a low-cost manufacture environment potential. In this work, we studied the morphology of the ink jet deposition of polyfluorene over Indium Tin Oxide (ITO) substrates treated by different procedures. Those materials where used because the polyfluorene polymer presents high light emission efficiency and easiness of processing. The electrodes were prepared with ITO (due its low resistivity, high work function and high transmittance in the visible spectrum) and aluminum. The processed displays were sealed inside an inert ambient with positive pressure to avoid the photo-oxidation of the semiconductor luminescent polymer layers. The devices were characterized by optical (photoluminescence), electrical (electroluminescence) and performance (brightness, luminous efficiency) measurements.

No description available.