We report on the fabrication of wholly polymeric onedimensional (1-D) photonic crystals (i.e., Bragg reflectors, Bragg mirrors) via solution processing for use in the near (NIR) and the short wave (SWIR) infrared spectrum (1−2 μm) with very high reflectance (R ∼ 90−97%). Facile fabrication of these highly reflective films was enabled by direct access to solution processable, ultrahigh refractive index polymers, termed, Chalcogenide Hybrid Inorganic/ Organic Polymers (CHIPs). The high refractive index (n) of CHIPs materials (n = 1.75−2.10) allowed for the production of narrow band IR Bragg reflectors with high refractive index contrast (Δn ∼ 0.5) when fabricated with low n polymers, such as cellulose acetate (n = 1.47). This is the highest refractive index contrast (Δn ∼ 0.5) demonstrated for an all-polymeric Bragg mirror which directly enabled high reflectivity from films with 22 layers or less. Facile access to modular, thin, highly reflective films from inexpensive CHIPs materials offers a new route to IR Bragg reflectors and other reflective coatings with potential applications for IR photonics, commercial sensing, and LIDAR applications.

The morphology of conjugated polymers has critical influences on electronic and optical properties of optoelectronic devices. Even though lots of techniques and methods are suggested to control the morphology of polymers, very few studies have been performed inducing high charge transport along out‐of‐plane direction. In this study, the self‐assembly of homo‐ and blended conjugated polymers which are confined in nanostructures is utilized. The resulting structures lead to high charge mobility along vertical direction for both homo‐ and blended conjugated polymers. Both semicrystalline and amorphous polymers show highly increased population of face‐on crystallite despite intrinsic crystallinity of polymers. They result in more than two orders of magnitude enhanced charge mobility along vertical direction revealed by nanoscale conductive scanning force microscopy and macroscale IV characteristic measurements. Moreover, blends of semicrystalline and amorphous polymers, which are known to show inferior optical and electrical properties due to their structural incompatibility, are formed into harmonious states by this approach. Assembly of blends of semicrystalline and amorphous polymers under nanoconfinement shows charge mobility in out‐of‐plane direction of 0.73 cm2 V−1 s−1 with wide range of absorption wavelength from 300 to 750 nm demonstrating the synergistic effects of two different polymers.

Block copolymers (BCPs) under nanoscale confinement can self-assemble to form novel nanostructures that are not available in the bulk state. Particularly, the ordering process of block copolymers and the resulting morphologies depend sensitively on the dimensionality, geometry, and surface property of the confining environment. In this study, we report on the self-assembled morphologies of polystyrene-block-1,4-polybutadiene (PS-b-PB) confined in conical pores of various sizes, shapes, and surface properties. Based on the experimental observations from transmission electron microscopy and theoretical calculation using the simulated annealing method, we found that the phase separation of PS-b-PB under the conical confinement is competitively determined by three thermodynamic factors: (1) the interfacial energy between two blocks, (2) the surface energy between the blocks and the surrounding environment (i.e., air and substrates), and (3) the entropic penalty associated with the large curvature at the vertices of conical pores. In addition, three-dimensional imaging of transmission electron microtomography was also performed in an attempt to gain more detailed information on the internal nanostructures of the BCP.

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In article number 1908087, Rüdiger Berger, Hyunsik Yoon, Kookheon Char, and co‐workers demonstrate the versatility of nanoconfinement on various semiconducting polymers for enhancing vertical charge transport. Both homogeneous and blended semiconducting polymers show more than two orders of magnitude higher charge mobility along the out‐of‐plane direction due to the enhanced crystallinity and compatibility of the polymers through the polymer assembly under nanoconfined geometries.