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High-power and lightweight photovoltaic (PV) modules are suitable for building-integrated photovoltaic (BIPV) systems. Due to the characteristics of the installation sites, the BIPV solar modules are limited by weight and installation area. In this study, we fabricated glass-free and shingled-type PV modules with an area of 1040 mm × 965 mm, which provide more conversion power compared to conventional PV modules at the same installed area. Further, we employed an ethylene tetrafluoroethylene sheet instead of a front cover glass and added an Al honeycomb sandwich structure to enhance the mechanical stability of lightweight PV modules. To optimize the conversion power of the PV module, we adjusted the amount of dispensed electrically conductive adhesives between the solar cells. Finally, we achieved a conversion power of 195.84 W at an area of 1.004 m2, and we performed standard reliability tests using a PV module that weighed only 9 kg/m2.

Nanoporous structures have attracted great attention in electronics, sensor and storage devices, and photonics because of their large surface area, large volume to surface ratio, and potential for high-sensitivity sensor applications. Normally, electron or ion beam patterning can be used for nanopores fabrication by direct writing. However, direct writing is a rather expensive and time-consuming method due to its serial nature. Therefore, it may not translate to a preferred manufacturing process. In this research, a perfectly ordered large-area periodic pattern in an area of approximately 1 cm2 has been successfully fabricated on various substrates including glass, silicon, and polydimethylsiloxane, using a two-step process comprising visible light-based multibeam interference lithography and subsequent pattern transfer processes of reactive ion etching and nanomolding. Additionally, the multibeam interference lithography templated anodized aluminum oxide process has been described. Since the fabrication area in multibeam interference lithography can be extended by using a larger beam size, it is highly cost effective and manufacturable. Furthermore, although not described here, an electrodeposition process can be utilized as a pattern transfer process. This large-area perfectly ordered nanopore array will be very useful for high-density electronic memory and photonic bandgap and metamaterial applications.

Interference lithography is a promising method for fabricating large-area, defect-free three-dimensional photonic crystal structures which can be used for facilitating the realization of photonic devices with a fast processing time. Although they can be used in waveguides, resonators, and detectors, their repeated regular array patterns can only be used for limited applications. In this study, we demonstrate a method for fabricating large-area photonic crystal structures with controlled defects by combining interference lithography and two-photon lithography using a light-curable resin. By combining regular array structures and controlled patterns, monotonous but large-area regular structures can be obtained. Furthermore, the patterned structures have considerable potential for use in various applications, such as solar cells, sensors, photodetectors, micro-/nano-electronics, and cell growth.

Transparent p-CuI/n-SiZnSnO (SZTO) heterojunction diodes are successfully fabricated by thermal evaporation of a (111) oriented p-CuI polycrystalline film on top of an amorphous n-SZTO film grown by the RF magnetron sputtering method. A nitrogen annealing process reduces ionized impurity scattering dominantly incurred by Cu vacancy and structural defects at the grain boundaries in the CuI film to result in improved diode performance; the current rectification ratio estimated at ±2 V is enhanced from ≈106 to ≈107. Various diode parameters, including ideality factor, reverse saturation current, offset current, series resistance, and parallel resistance, are estimated based on the Shockley diode equation. An energy band diagram exhibiting the type-II band alignment is proposed to explain the diode characteristics. The present p-CuI/n-SZTO diode can be a promising building block for constructing useful optoelectronic components such as a light-emitting diode and a UV photodetector.

Effective incident light should be controlled for improving the current density of solar cells by employing nano- and micro-structures on silicon surface. The elastomeric stamp process, which is more cost effective and simpler than conventional photolithography, was proposed for the fabrication of nano- and micro-structures. Polydimethylsiloxane (PDMS) was poured on a mother pattern with a diameter of 6 μm and a spacing of 2 μm; then, curing was performed to create a PDMS mold. The regular micropattern was stamped on a low-viscosity resin-coated silicon surface, followed by the simple reactive ion etching process. Nano-structures were formed using the Ag-based electroless etching process. As etching time was increased to 6 min, reflectance decreased to 4.53% and current density improved from 22.35 to 34.72 mA/cm2.

It is beneficial to reduce thickness of high-purity of c-Si wafer for cost-effective water splitting system based on silicon photoelectrode. However, a thin Si absorber causes insufficient absorption of light and it should be needed to solve problems. Here, a 21-µm-thin Si photoanode for which a NiOx-coated silicon nanopyramid (SiNP) is employed is presented as a solution. The NiOx/n-SiNP structures improved the light absorption as well as the total number of catalytic sites to enable photo-oxidation reactions. A photocurrent of 7.7 mA/cm² was generated at the equilibrium potential of the OER (EOER = 1.23 V vs. a reversible hydrogen electrode in a 1 M KOH solution). Also, the photoanode did not show any degradation over the 24 hr of a photoelectrochemical water-oxidation process. [ABSTRACT FROM AUTHOR]