RESUMO
Light extraction improvement is still an important issue for active-matrix organic light-emitting diode displays (AMOLEDs). In our previous work, a three-dimensional (3D) reflective pixel configuration embedding the OLED in the concave 3D reflector and patterned high-index filler had been proposed for significant enhancement of the pixel light extraction. In this work, influences of thin film encapsulation (TFE) on light extraction of such reflective 3D OLED pixels are considered as well by simulation studies. Unfortunately, the optical simulation reveals strong reduction of the light extraction efficiency induced by TFE layers. As such, an additional angle-selective optical film structure between the pixel and the encapsulation layers is introduced to control the angular distribution of the light coupled into the encapsulation layers and to solve TFE-induced optical losses. As a result, TFE-induced losses can be substantially reduced to retain much of light extraction efficiency. The results of this study are believed to provide useful insights and guides for developing even more efficient and power-saving AMOLEDs.
RESUMO
Despite stringent power consumption requirements in many applications, over years organic light-emitting diode (OLED) displays still suffer unsatisfactory energy efficiency due to poor light extraction. Approaches have been reported for OLED light out-coupling, but they in general are not applicable for OLED displays due to difficulties in display image quality and fabrication complexity and compatibility. Thus to date, an effective and feasible light extraction technique that can boost efficiencies and yet keep image quality is still lacking and remains a great challenge. Here, a highly effective and scalable extraction-enhancing OLED display pixel structure is proposed based on embedding the OLED inside a three-dimensional reflective concave structure covered with a patterned high-index filler. It can couple as much internal emission as possible into the filler region and then redirect otherwise confined light for out-coupling. Comprehensive multi-scale optical simulation validates that ultimately high light extraction efficiency approaching ≈80% and excellent viewing characteristics are simultaneously achievable with optimized structures using highly transparent top electrodes. This scheme is scalable and wavelength insensitive, and generally applicable to all red, green, and blue pixels in high-resolution full-color displays. Results of this work are believed to shed light on the development of future generations of advanced OLED displays.
RESUMO
<p><b>OBJECTIVE</b>To study the regulation of anoikis by tyrosine kinase receptor B (TrkB) in human nasopharyngeal carcinoma lines. METHODS; Expression levels of TrkB and brain-derived neurotrophic factor (BDNF) were evaluated by RT-PCR and Western blot. Colony formation ability of C666-1 was observed in soft agar. Proliferation rate and apoptosis, that change in cells by treating the TrkB inhibitor K252a and specificity ligand BDNF respectively under suspension culture, were measured by cell counting kit-8 (CCK-8) assay and the flow cytometry assay. The expression change of TrkB, BDNF and phosphorylation of serine threonine kinase (p-Akt) were investigated by Western blot analysis.</p><p><b>RESULTS</b>TrkB and BDNF were identified in C666-1 cells. C666-1 cells could be decreased the proliferation of colony in soft agar by effect of K252a, but BDNF could make the colony prolific. K252a can inhibit the expression of TrkB in C666-1, and prevent p-Akt activation. And exogenous BDNF stimulated up-regulation TrkB and p-Akt, induced anoikis resistance.</p><p><b>CONCLUSION</b>TrkB inhibits anoikis in nasopharyngeal carcinoma cells. Inhibiton of TrkB by K252a can induce anoikis, and may prove particularly effective in treatment of nasopharyngeal carcinoma.</p>
