Nanoparticle scattering layer based on polymer-metal oxide composite is successfully introduced to enhance the light extraction efficiency of organic light emitting diodes (OLEDs). We find that the density and the distribution of nanoparticles is the key factor to maximize the light extraction efficiency of pristine OLEDs by out-coupling the unusable light with the scattering film. In our experiment, 71 wt% of Al₂O₃ mixed with polymer matrix shows the increase of light extraction efficiency of 40%. This method is expected to play a critical role to create the low-power OLED application such as OLED lightings with simple fabrication process and low cost.

Interfacial doping in organic semiconductors (OSs) is an important technique to achieve efficient organic electronic devices. In this paper, we discuss how the charge injection into an OS can be enhanced by the insertion of a thin interfacial layer or an electrically doped OS layer between an electrode and an undoped OS. We present that the vacuum level shift and Fermi level modification by the electrical doping is the origin of the efficient charge injection through a metal–organic junction and an organic–organic junction. Application to organic electronics such as organic light‐emitting diodes (OLEDs) and organic photovoltaics (OPVs) is briefly summarized.

We investigated layered titanium nitride (TiN) and aluminum nitride (AlN) for color glasses in building integrated photovoltaic (BIPV) systems. AlN and TiN are among suitable and cost-effective optical materials to be used as thin multilayer films, owing to the significant difference in their refractive index. To fabricate the structure, we used radio frequency magnetron deposition method to achieve the target thickness uniformly. A simple, fast, and cheap fabrication method is achieved by depositing the multilayer films in a single sputtering chamber. It is demonstrated that a multilayer stack that allows light to be transmitted from a low refractive index layer to a high refractive index layer or vice-versa can effectively create various distinct color reflections for different film thicknesses and multilayer structures. It is investigated from simulation based on wave optics that TiN/AlN multilayer offers better color design freedom and a cheaper fabrication process as compared to AlN/TiN multilayer films. Blue, green, and yellow color glasses with optical transmittance of more than 80% was achieved by indium tin oxide (ITO)-coated glass/TiN/AlN multilayer films. This technology exhibits good potential in commercial BIPV system applications.

This study proposes front colored glass for building integrated photovoltaic (BIPV) systems based on multi-layered derivatives of glass/MoO₃/Al₂O₃ with a process technology developed to realize it. Molybdenum oxide (MoO₃) and aluminum oxide (Al₂O₃) layers are selected as suitable candidates to achieve thin multi-layer color films, owing to the large difference in their refractive indices. We first investigated from a simulation based on wave optics that the glass/MoO₃/Al₂O₃ multi-layer type offers more color design freedom and a cheaper fabrication process when compared to the glass/Al₂O₃/MoO₃ multi-layer type. Based on the simulation, bright blue and green were primarily fabricated on glass. It is further demonstrated that brighter colors, such as yellow and pink, can be achieved secondarily with glass/MoO₃/Al₂O₃/MoO₃ due to enhanced multi-interfacial reflections. The fabricated color glasses showed the desired optical properties with a maximum transmittance exceeding 80%. This technology exhibits promising potential in commercial BIPV system applications.