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Nano texturing has been confirmed as an effective structure to improve the efficiency of multi-crystalline silicon solar cells by reducing optical loss. In this study, nano textured solar cells are fabricated by the Reactive Ion Etching (RIE) method based on a conventional production line. Several characterization methods are employed to evaluate the morphology, minority carrier lifetime, quantum efficiency and electricity performance of both nano textured and micro textured solar cells. The results show that nano textured solar cells have a maxiumum efficiency of 19.21 % and an average efficiency that is 0.57 % higher than that of micro textured solar cells. Thus, the RIE method is an effective way to manufacture nano textured solar cells. It can demonstrably improve the photoelectric conversion efficiency of mass-produced solar cells and reduce the production cost, which is significant to the development of solar cell industy. DOI: http://dx.doi.org/10.5755/j01.ms.24.2.17398

Femtosecond laser-based Nonlinear Laser Lithography (NLL) was applied to AISI 316L stainless steel, which requires surface modification to achieve satisfactory tribological behaviour. NLL advances over the well-known Laser Induced Periodic Surface Structures (LIPSS) in terms of uniformity and long-range order of high speeds, over large areas. A galvanometric scanner head was used for an high production rate. Dry and lubricated sliding tests, considering different orientations of the nanotexture showed that COF values after NLL treatment are significantly lower. In lubricated tests, COF values of NLL-treated surfaces are nearly half the values of untreated surfaces, whereas the difference further increases when measured in dry conditions, where the orientation of the surface texturing influences the results.

Structural colouration is a well-known “bio-inspired” phenomenon that explains the astonishing natural iridescence of several animals’ skin, such as: fish scales, birds’ feathers, butterflies’ wings, flowers and more beauties in nature. The phenomenon occurs when light diffracts due to the topology of the just mentioned surfaces independently from radiation-based colouring or pigmentation. In recent years, the rise of nanotechnology has brought about the possibility to design and reproduce structural colours on consumer products [1]. In this study, structural colours are proposed as decorative features for plastic substrates. Periodic sub-micro gratings showing a variable pitch (400 – 1500 nm) and step height (300 – 1000 nm) are manufactured in a cleanroom by means of nanoimprinting lithography on steel inserts. Gratings are subsequently replicated on plastic products by means of polymer injection moulding. This study focuses on understanding the technology readiness, highlighting limitations and advantages of the adoption of structural colours in plastic consumer products. Aspects related to different polymer replication techniques of the nanostructures, metrological challenges to ensure manufacturing accuracy and precision of the mentioned features, the durability of the plastic gratings and the durability of the nanoimprinted injection moulding inserts would be key factors in understanding the applicability of structural decoration in the plastic industry.