Atomic layer deposition: an overview.

Worldwide commercial interest in carbon nanotubes (CNTs) is reflected in a production capacity that presently exceeds several thousand tons per year. Currently, bulk CNT powders are incorporated in diverse commercial products ranging from rechargeable batteries, automotive parts, and sporting goods to boat hulls and water filters. Advances in CNT synthesis, purification, and chemical modification are enabling integration of CNTs in thin-film electronics and large-area coatings. Although not yet providing compelling mechanical strength or electrical or thermal conductivities for many applications, CNT yarns and sheets already have promising performance for applications including supercapacitors, actuators, and lightweight electromagnetic shields.

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Carbon Nanotubes: Present and Future Commercial Applications

2.2. Materials 929 2.3. Factors Influencing Charge Mobility 931 2.3.1. Molecular Packing 931 2.3.2. Disorder 932 2.3.3. Temperature 933 2.3.4. Electric Field 934 2.3.5. Impurities 934 2.3.6. Pressure 934 2.3.7. Charge-Carrier Density 934 2.3.8. Size/molecular Weight 935 3. The Charge-Transport Parameters 935 3.1. Electronic Coupling 936 3.1.1. The Energy-Splitting-in-Dimer Method 936 3.1.2. The Orthogonality Issue 937 3.1.3. Impact of the Site Energy 937 3.1.4. Electronic Coupling in Oligoacene Derivatives 938

Charge transport in organic semiconductors.

Since the discovery of mechanically exfoliated graphene in 2004, research on ultrathin two-dimensional (2D) nanomaterials has grown exponentially in the fields of condensed matter physics, material science, chemistry, and nanotechnology. Highlighting their compelling physical, chemical, electronic, and optical properties, as well as their various potential applications, in this Review, we summarize the state-of-art progress on the ultrathin 2D nanomaterials with a particular emphasis on their recent advances. First, we introduce the unique advances on ultrathin 2D nanomaterials, followed by the description of their composition and crystal structures. The assortments of their synthetic methods are then summarized, including insights on their advantages and limitations, alongside some recommendations on suitable characterization techniques. We also discuss in detail the utilization of these ultrathin 2D nanomaterials for wide ranges of potential applications among the electronics/optoelectronics, electrocat...

Recent Advances in Ultrathin Two-Dimensional Nanomaterials

All of the cations currently used in perovskite solar cells abide by the tolerance factor for incorporation into the lattice. We show that the small and oxidation-stable rubidium cation (Rb + ) can be embedded into a “cation cascade” to create perovskite materials with excellent material properties. We achieved stabilized efficiencies of up to 21.6% (average value, 20.2%) on small areas (and a stabilized 19.0% on a cell 0.5 square centimeters in area) as well as an electroluminescence of 3.8%. The open-circuit voltage of 1.24 volts at a band gap of 1.63 electron volts leads to a loss in potential of 0.39 volts, versus 0.4 volts for commercial silicon cells. Polymer-coated cells maintained 95% of their initial performance at 85°C for 500 hours under full illumination and maximum power point tracking.

https://science.sciencemag.org/content/sci/early/2016/09/28/science.aah5557.full.pdf

Incorporation of rubidium cations into perovskite solar cells improves photovoltaic performance

Increasing the light extraction efficiency has been widely studied for highly efficient organic light-emitting diodes (OLEDs). Among many light-extraction approaches proposed so far, adding a corrugation layer has been considered a promising solution for its simplicity and high effectiveness. While the working principle of periodically corrugated OLEDs can be qualitatively explained by the diffraction theory, dipolar emission inside the OLED structure makes its quantitative analysis challenging, making one rely on finite-element electromagnetic simulations that could require huge computing resources. Here, we demonstrate a new simulation method, named the diffraction matrix method (DMM), that can accurately predict the optical characteristics of periodically corrugated OLEDs while achieving calculation speed that is a few orders of magnitude faster. Our method decomposes the light emitted by a dipolar emitter into plane waves with different wavevectors and tracks the diffraction behavior of waves using diffraction matrices. Calculated optical parameters show a quantitative agreement with those predicted by finite-difference time-domain (FDTD) method. Furthermore, the developed method possesses a unique advantage over the conventional approaches that it naturally evaluates the wavevector-dependent power dissipation of a dipole and is thus capable of identifying the loss channels inside OLEDs in a quantitative manner.

Fast and rigorous optical simulation of periodically corrugated light-emitting diodes based on a diffraction matrix method.

A thermally evaporated p -type amorphous tungsten oxide ( p-a- WO 3 ) film was introduced as a novel buffer layer between SnO 2 and p -type amorphous silicon carbide ( p-a -SiC) of pin -type amorphous silicon ( a -Si) based solar cells. By using this film, a-Si solar cells with a p-a -WO 3 /p-a -SiC double p-layer structure were fabricated and the cell photovoltaic characteristics were investigated as a function of p-a -WO 3 layer thickness. By inserting a 2 nm-thick p-a -WO 3 layer between SnO 2 and a 6 nm-thick p-a -SiC layer, the short circuit current density increased from 9.73 to 10.57 mA/cm 2 , and the conversion efficiency was enhanced from 5.17 % to 5.98 %.

Improving performance of amorphous silicon solar cells using tungsten oxide as a novel buffer layer between the sno2/p-a-SiC interface

An organic light emitting device having increased outcoupling efficiency, a lighting apparatus including the organic light emitting device, and an organic light emitting display apparatus including the organic light emitting device. The organic light emitting device includes a substrate, a first electrode layer that is uniformly patterned on the substrate, a low refractive conductive layer disposed on the first electrode layer, and having a conductive material with a lower refractive index than a refractive index of an organic layer that is disposed on the low refractive conductive layer, and a second electrode layer formed on the organic layer.

Organic light emitting device, lighting apparatus and organic light emitting display apparatus

The stress relief layer is an effective method to fabricated stretchable OLEDs with minimal compromise in performance. Stretchable OLEDs fabricated by this method have very little change in efficiency even when interconnectors are stretched 140%.

Seunghyup Yoo

Papers

Fast and rigorous optical simulation of periodically corrugated light-emitting diodes based on a diffraction matrix method.

Improving performance of amorphous silicon solar cells using tungsten oxide as a novel buffer layer between the sno2/p-a-SiC interface

Organic light emitting device, lighting apparatus and organic light emitting display apparatus

Realization of stretchable OLEDs through the stacked structure of stress relief layer and stretchable platform

Realization of foldable perovskite light-emitting diodes