Herein, we report a facile and robust route to nanoscale tunable triboelectric energy harvesters realized by the formation of highly functional and controllable nanostructures via block copolymer (BCP) self-assembly. Our strategy is based on the incorporation of various silica nanostructures derived from the self-assembly of BCPs to enhance the characteristics of triboelectric nanogenerators (TENGs) by modulating the contact-surface area and the frictional force. Our simulation data also confirm that the nanoarchitectured morphologies are effective for triboelectric generation.

Deterministic positioning and assembly of colloidal nanoparticles (NPs) onto substrates is a core requirement and a promising alternative to top down lithography to create functional nanostructures and nanodevices with intriguing optical, electrical, and catalytic features. Capillaryassisted particle assembly (CAPA) has emerged as an attractive technique to this end, as it allows controlled and selective assembly of a wide variety of NPs onto predefined topographical templates using capillary forces. One critical issue with CAPA, however, lies in its final printing step, where high printing yields are possible only with the use of an adhesive polymer film. To address this problem, we have developed a template dissolution interfacial patterning (TDIP) technique to assemble and print single colloidal AuNP arrays onto various dielectric and conductive substrates in the absence of any adhesion layer, with printing yields higher than 98%.The TDIP approach grants direct access to the interface between the AuNP and the target surface, enabling the use of colloidal AuNPs as building blocks for practical applications. The versatile applicability of TDIP is demonstrated by the creation of direct electrical junctions for electro-and photoelectrochemistry and nanoparticle-on-mirror geometries for single particle molecular sensing.

The next-generation wearable near-eye displays inevitably require extremely high pixel density due to significant decrease in the viewing distance. For such denser and smaller pixel arrays, the emissive material must exhibit wider colour gamut so that each of the vast pixels maintains the colour accuracy. Electroluminescent quantum dot light-emitting diodes are promising candidates for such application owing to their highly saturated colour gamuts and other excellent optoelectronic properties. However, previously reported quantum dot patterning technologies have limitations in demonstrating full-colour pixel arrays with sub-micron feature size, high fidelity, and high post-patterning device performance. Here, we show thermodynamic-driven immersion transfer-printing, which enables patterning and printing of quantum dot arrays in omni-resolution scale; quantum dot arrays from single-particle resolution to the entire film can be fabricated on diverse surfaces. Red-green-blue quantum dot arrays with unprecedented resolutions up to 368 pixels per degree is demonstrated.

Directed self-assembly (DSA) of block copolymers (BCPs) with a high Flory−Huggins interaction parameter (χ) provides advantages of pattern size reduction below 10 nm and improved pattern quality. Despite theoretical predictions, however, the questions of whether BCPs with a much higher χ than conventional high-χ BCPs can further improve the line edge roughness (LER) and how to overcome their extremely slow self-assembly kinetics remain unanswered. Here, we report the synthesis and assembly of poly-(4vinylpyridine-b-dimethylsiloxane) BCP with an extremely high χ-parameter (estimated to be approximately 7 times higher compared to that of poly(styrene-b-dimethylsiloxane) − a conventional high-χ BCP) and achieve a markedly low 3σ line edge roughness of 0.98 nm, corresponding to 6% of its line width. Moreover, we demonstrate the successful application of an ethanolbased 60 °C warm solvent annealing treatment to address the extremely slow assembly kinetics of the extremely high-χ BCP, considerably reducing the self-assembly time from several hours to a few minutes. This study suggests that the use of BCPs with an even larger χ could be beneficial for further improvement of self-assembled BCP pattern quality.

Achieving high emission efficiency in solidstate quantum dots (QDs) is an essential requirement for high-performance QD optoelectronics. However, most QD films suffer from insufficient excitation and light extraction efficiencies, along with nonradiative energy transfer between closely adjacent QDs. Herein, we suggest a highly effective strategy to enhance the photoluminescence (PL) of QD composite films through an assembly of QDs and poly-(styrene-b-4-vinylpyridine)) (PS-b-P4VP) block copolymer (BCP). A BCP matrix casted under controlled humidity provides multiscale phase-separation features based on (1) submicrometer-scale spinodal decomposition between polymer-rich and water-rich phases and (2) sub-10 nm-scale microphase separation between polymer blocks. The BCP-QD composite containing bicontinuous random pores achieves significant enhancement of both light absorption and extraction efficiencies via effective random light scattering. Moreover, the microphase-separated morphology substantially reduces the Forster resonance energy transfer efficiency from 53% (pure QD film) to 22% (BCP-QD composite), collectively achieving an unprecedented 21-fold enhanced PL over a broad spectral range.