Light trapping by nanostructures featuring high transmittance and high haze represents a viable strategy to boost solar cell efficiency via enhanced light absorption. However, low-cost, large-area, and eco-friendly fabrication approaches for such light trapping structures remain elusive. Herein, we demonstrate a new design of film with multiply indented, hybrid three-dimensional (3D)-nanobowls, which can reduce light reflection at large angles by together enhancing light scattering, transmittance, and haze. This kind of nanostructures is generated via roll-to-roll (R2R) UV-nanoimprint process, where the critical template is fabricated by taking advantage of metal displacement reaction between aluminum and zinc ions. The as-fabricated light-trapping film shows ultra-high haze of 98% while keeping favorable transmittance of 87%. Therefore, this light-trapping film, adhered onto polysilicon solar cells, enhances the short-circuit current (J_SC) from 4.26% at solar illumination angle of 0°, up to 65.95% at large angle of 85°, as well as 14.29% onto organic solar cells (OSC) under indoor light. To validate practical feasibility, day-time (13-hour) outdoor large-format polysilicon cells experiments reveal that the J_SC was enhanced by 5.68% under the sunny condition and 13.6% under the cloudy condition. Furthermore, this film exhibits self-cleaning performance with a water contact angle (WCA) of up to 140°. More importantly, this kind of high-performance film can be fabricated up to more than 25 m within 1 min using our R2R process, demonstrating the high throughput and low cost capability, well meeting the demand for solar cell industry.

The capability to consistently manufacture structures with sub-5 nm features has greatly accelerated scientific advancements in nanoscience and nanotechnology. However, most current methods are serial processes that are time-consuming and impractical for large-scale manufacturing at the sub-5 nm level. The challenge of achieving scalable and reproducible production of sub-5 nm structures poses a significant hurdle for both fundamental research and commercial implementations. In this review, we explore some representative sub-5 nm fabrication strategies, focusing on approaches that facilitate scalable and reproducible manufacturing. We highlight the most promising techniques such as extreme ultraviolet lithography, electron beam lithography, directed self-assembly and atomic layer lithography that hold potential breakthroughs in both research and industry, based on criteria such as resolution, scalability, reproducibility and their applicability in photonics such as surface-enhanced spectroscopies, terahertz science, and nonlinear optics, as well as in electronics such as quantum devices, molecular devices and memory devices. The evolution of scalable and reproducible sub-5 nm manufacturing methods will ultimately revolutionize next-generation devices, encompassing quantum technologies, neuromorphic computing chips, and the mass production of integrated circuits.

Surface nanopatterning of semiconductor optoelectronic devices is a powerful way to improve their quality and performance. However, photoelectric devices’ inherent stress sensitivity and inevitable warpage pose a huge challenge on fabricating nanostructures large-scale. Electric-driven flexible-roller nanoimprint lithography for nanopatterning the optoelectronic wafer is proposed in this study. The flexible nanoimprint template twining around a roller is continuously released and recovered, controlled by the roller’s simple motion. The electric field applied to the template and substrate provides the driving force. The contact line of the template and the substrate gradually moves with the roller to enable scanning and adapting to the entire warped substrate, under the electric field. In addition, the driving force generated from electric field is applied to the surface of substrate, so that the substrate is free from external pressure. Furthermore, liquid resist completely fills in microcavities on the template by powerful electric field force, to ensure the fidelity of the nanostructures. The proposed nanoimprint technology is validated on the prototype. Finally, nano-grating structures are fabricated on a gallium nitride light-emitting diode chip adopting the solution, achieving polarization of the light source.

The integrated perception capable of detecting and monitoring varieties of activities is one of the ultimate purposes of wearable electronics and intelligent robots. Limited by the space occupation, it lacks practical feasibility to stack multiple types of single sensors on each other. Herein, a high-sensitivity dual-function capacitive sensor with proximity sensing and pressure sensing is proposed. The fringing electric field can be confined in the proximity-sensitive area by fibrous loop-patterned electrode, leading to more stolen charges when object approaching and thus a high proximity sensitivity. The high-permittivity doped structured dielectric layer reduces the compressive stiffness and enhances the rate of compression-caused increase in the equivalent relative permittivity of the dielectric layer, resulting in a larger increase in capacitance and thus a high pressure sensitivity. The electrodes and dielectric layer together compose the capacitor and act as the sensor without taking up additional space. The decoupling of proximity-sensing and pressure-sensing modes can be achieved by decrease or increase in capacitance. Combined with array distribution and sequential scanning, the sensors can be used for detection of motion trajectory, contour recognition, and pressure distribution.

Non-planar morphology is a common feature of devices applied in various physical fields, such as light or fluid, which pose a great challenge for surface nano-patterning to improve their performance. The present study proposes a discretely-supported nanoimprint lithography (NIL) technique to fabricate nanostructures on the extremely non-planar surface, namely high-spatial-frequency stepped surface. The designed discretely imprinting template implanted a discretely-supported intermediate buffer layer made of sparse pillars arrays. This allowed the simultaneous generation of air-cushion-like buffer and reliable support to the thin structured layer in the template. The resulting low bending stiffness and distributed concentrated load of the template jointly overcome the contact difficulty with a stepped surface, and enable the template to encase the stepped protrusion as tight as possible. Based on the proposed discretely-supported NIL, nanostructures were fabricated on the luminous interface of light emitting diodes chips that covered with micrometer step electrodes pad. About 96% of the utilized indium tin oxide transparent current spreading layer surface on top of the light emitting diode (LED) chips was coated with nanoholes array, with an increase by more than 40% in the optical output power. The excellent ability of nanopatterning a non-planar substrate could potentially lead innovate design and development of high performance device based on discretely-supported NIL.