Building-integrated photovoltaics (BIPV) comprise the integration of a solar power generation system into the exterior design and architectural elements of a building to produce electricity, which allows the building itself to generate electricity. By integrating shingled technology into the photovoltaic module with optimization of the optical effect, the output performance of the module can be increased while securing an aesthetic appeal as an architectural exterior material for the building simultaneously. In this research, we studied enhancing the performance of BIPV modules through an analysis of the optical coupling effect for shingled technology using PSpice simulation. Compared to the efficiency of 0.2 cm string spacing, the optical coupling effect was increased by 33.33%, 46.98%, 67.01%, and 193.49% according to the string spacing of 0.5 cm, 1 cm, 2 cm and 4 cm, respectively. To analyze this increase, we focused on studying the increase in current due to the reflection and re-absorption of light in the back layer of the solar cell as the cause of this output enhancement. Additionally, the coupling effect in accord with different layers showed that using white EVA to reflect the incident light from the top layer resulted in 117.14% and 521.90% enhancements in maximum output power (Pm) loss % compared to the conventional and black backsheet applied PV modules, respectively.

The floating PV power system using with shingled modules to maximize power generation efficiency and its performance was analyzed through August 2020 to December 2020. The proposed system using the shingled module and its generated energy output was 20–30% more than the conventional PV system. Considering LCOE, it could be expected 22.223% reduction of LCOE and this power generation system which combines floating photovoltaic system and shingled modules is expected to have excellent economic feasibility as well as carbon reduction effects.

Smart buildings and near‐zero‐energy buildings require building integrated photovoltaic systems to minimize energy consumption and achieve photocommunication. Windows can be the next replaceable entity in smart buildings with smart photocommunication windows. It can provide a novel means of wireless and secured communication. The transparent photovoltaics (TPV) based photocommunication window can also produce on‐site power to provide power to run applications of internet of things. A TPV device can be used as the receiver to collect the encoded signals, and its physical flexibility is imperative to its installation on any curved surfaces. In this work, a Ga 2 O 3 /Cu 2 O heterojunction‐based flexible TPV (FTPV) that acts as a photocommunication window to sense Morse code‐embedded photosignals is developed and power is produced. The FTPV provides a high open‐circuit voltage of 613 mV with an average visible transmittance of 52.3%. The device is capable of detecting broadband photoresponses in the range from UV to NIR. The FTPV also remains highly robust after a number of cycles of bending and continues to record Morse code signals over a wide range of broadband photosignals. It also has an ultra‐UV‐blocking feature that makes it suitable for use to prevent chronic diseases caused by exposure to UV radiation.

The dispersion of a chiral polymer in a polymerizable matrix can amplify the chirality of the material, and a helical conformation of the chiral material within the polymerized SU-8 excessively increased the circular dichroism. Here, we demonstrate the fabrication of three-dimensional nanostructures of chiral/achiral mixtures by two-photon lithography. The irradiation of light and annealing caused local changes in the chiral material and finally led to the enhancement of the optical properties. The demonstration of a photopatternable chiral material could expand the usage of optical materials for various applications.

Alternative photo-sintering techniques for thermal annealing processes are used to improve the morphology, layer properties, and enhance solar cell performance. The fast, nontoxic, low cost, and environmentally friendly characteristics of Cu2ZnSnS4 have led to its consideration as an alternative potential absorber layer in copper indium gallium diselenide thin film solar cells. This work investigates the photo-sintering process for the absorber layer of Cu2ZnSnS4 solar cells. A Cu2ZnSnS4 layer was grown by hot-injection and screen-printing techniques, and the characteristics of the photo-sintered Cu2ZnSnS4 layer were evaluated by X-ray Diffraction, Raman spectroscopy, Energy dispersive X-ray analysis, Ultraviolet-visible spectroscopy, and field emission scanning electron microscopes. Overall, the optimal composition was Cu-poor and Zn-rich, without a secondary phase, estimated optical band-gap energy of approximately 1.6 eV, and enhanced morphology and kesterite crystallization. Using an intensity pulse light technique to the CZTS layer, fabrication of the solar cell device demonstrated successfully, and the efficiency of 1.01% was achieved at 2.96 J/cm2.

As new technologies for high-performance PV modules are developed and applied, the cost of the PV modules is also increasing. To reduce the consumption of Ag paste used for the high-power shingled PV module, a new patterns of electrode design is needed. Accordingly, we focused on reducing the consumption of Ag paste used for the metallization of solar cells by designing busbar-free electrode patterns suitable for shingled photovoltaic modules. In this paper, we introduced the busbar-free design of the electrode patterns on the front and rear side of the crystalline silicon solar cells. Based on the conventional and the busbar free designs, the shingled string of each type of electrode pattern was manufactured and its characteristics were investigated. The efficiency of the busbar-free type of shingled string was almost the same as that of the string having the conventional pattern. The proposed electrode pattern did not affect the efficiency or output power of the shingled module, while the amount of Ag usage in the solar cells was reduced by more than 60%. As a result, we confirmed that the busbar free electrode pattern proposed in this study was suitable for a cost-effective shingled PV module.

In the case of the existing power equipment business, a variety of insulation and accessories is manufactured with petroleum-based epoxy resins. However, as petrochemical resources are gradually limited and concerns about the environment and economy grow, the power equipment industry has recently studied many insulating materials using bio-based epoxy to replace petroleum feedstock-based products in order to produce insulators using eco-friendly materials. In this paper, the simulation of the automatic pressure gelation process was performed by obtaining parameter values of curing kinetics and chemical rheology through physical properties analysis of bio-based epoxy complexes and applying them to Moldflow software. The simulation results were compared and analyzed according to the temperature control of each heater in the mold, while considering the total curing time, epoxy flow, and curing condition. A temperature condition of 140 °C/140 °C/135 °C/135 °C/130 °C/130 °C/120 °C/120 °C provided the optimal curing conditions. Based on the temperature conditions of the simulation results, the actual GIS spacer was manufactured, and x-ray inspection was performed to check the moldability.

Floating solar power has a higher power generation efficiency than existing solar power generation methods. It is easier to secure in an installation area as well as to connect to other renewable energy sources. Floating solar power is considered an essential component for achieving carbon neutrality because it compensates for the shortcomings of existing solar power systems and maximizes their advantages. In this study, a performance comparison was conducted between pivotless tracking-type and fixed-type solar power systems. These systems were installed at the Irwol Reservoir in Suwon, South Korea, and monitored for comparison between May 2019 and June 2020. The tracking-type system generated approximately 14% more energy than the fixed-type system; the performance was maximized in May, which showed 25.63% more output power, and the performance was minimized in winter, with 3% more generated power. Owing to its pivotless structure, this system can be used in the solar industry.

At the core of the climate crisis lies excessive carbon emissions from the continued use of fossil fuels [...]

We report the effects of H2S passivation on the effective minority carrier lifetime of crystalline silicon (c-Si) wafers. c-Si wafers were thermally annealed under an H2S atmosphere at various temperatures. The initial minority carrier lifetime (6.97 μs) of a c-Si wafer without any passivation treatments was also measured for comparison. The highest minority carrier lifetime gain of 2030% was observed at an annealing temperature of 600 °C. The X-ray photoelectron spectroscopy analysis revealed that S atoms were bonded to Si atoms after H2S annealing treatment. This indicates that the increase in minority carrier lifetime originating from the effect of sulfur passivation on the silicon wafer surface involves dangling bonds.

Shingled photovoltaic (PV) modules with increased output have attracted growing interest compared to conventional PV modules. However, the area per unit solar cell of shingled PV modules is smaller because these modules are manufactured by dividing and bonding solar cells, which means that shingled PV modules can easily have inferior shading characteristics. Therefore, analysis of the extent to which the shadow affects the output loss is essential, and the circuit needs to be designed accordingly. In this study, the loss resulting from the shading of the shingled string used to manufacture the shingled module was analyzed using simulation. A divided cell was modeled using a double-diode model, and a shingled string was formed by connecting the cell in series. The shading pattern was simulated according to the shading ratio of the vertical and horizontal patterns, and in the case of the shingled string, greater losses occurred in the vertical direction than the horizontal direction. In addition, it was modularized and compared with a conventional PV module and a shingled PV module. The results confirmed that the shingled PV module delivered higher shading output than the conventional PV module in less shade, and the result of the shading characteristic simulation of the shingled PV module was confirmed to be accurate within an error of 1%.

In recent printed electronics technology, a photo-sintering technique using intense pulsed light (IPL) source has attracted attention, instead of conventional a thermal sintering process with long time and high temperature. The key principle of the photo-sintering process is the selective heating of a thin film with large light absorption coefficients, while a transparent substrate does not heat by the IPL source. Most research on photo-sintering has used a xenon flash lamp as a light source. However, the xenon flash lamp requires instantaneous high power and is unsuitable for large area applications. In this work, we developed a new photo-sintering system using a high-power ultraviolet light emitting diode (UV-LED) module. A LED light source has many merits such as low power consumption and potential large-scale application. The silver nanoparticles ink was inkjet-printed on a polyethylene terephthalate (PET) and photo-sintered by the UV-LED module with the wavelength of 365 and 385 nm. The electrical resistivity as low as 5.44 × 10−6 Ω·cm (just about three times compared to value of bulk silver) was achieved at optimized photo-sintering conditions (wavelength of 365 nm and light intensity of 300 mW/cm2).

Injection molding is used in many industrial fields such as home appliances, vehicle parts, and electronic device parts because various resins can be molded, leading to mass production of complex shapes. Generally, the empirical prediction method is used to set the initial processing conditions of injection molding. However, this approach requires a lot of cost and its presented solution is not accurate. In this paper, injection molding was simulated through the MoldflowTM in order to manufacture the spacer for gas insulated switch. Through the simulation, the flow of the resin with respect to the diameter of the inlet was analyzed. It was found that the process was possible at a higher resin temperature as the diameter of the inlet increased. In addition, through thermal analysis during injection of the resin, it was confirmed that a stagnation phenomenon occurred at the insert portion during injection molding, and the temperature of the resin was higher than that of the mold. As in this paper, if the spacer is manufactured by optimizing the injection hole and the temperature of the injection process based on simulation, it is expected that the spacer can be manufactured with high productivity.

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 cm(2) 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.

BIPV modules have many advantages, but they are expensive to install, so it is important to increase the persistence of BIPV modules. To increase the durability of the BIPV module, one of the key components, the encapsulant, was changed to extend the life of the BIPV module and measure the efficiency. Because the core elements of the BIPV module and the PV module are the same, the output before and after deterioration of the PV module made of each encapsulant was compared.

Thin c-Si-based photoelectrochemical cells are regarded as one of the most promising alternatives to ensure costeffectiveness of water-splitting systems. In this work, we demonstrate a lithium fluoride (LiFX) layer as an electron-selective contact for cost-competitive 30-mu m thick c-Si photoanode devices. To ensure low contact resistance through LiFX/Al contacts on c-Si substrates is demonstrated; due to this low-resistance contact, efficient oxygen-evolution reactions might increase. We achieve an onset-voltage reduction with a cathodic shift of approximately 233 mV and an overpotential reduction of approximately 270 mV at 10 mA/cm(2) in a 1 M KOH solution. These results offer a cost-effective enhancement of thin c-Si photoelectrodes for water-splitting systems.

Shingled string technology can be used to maximize the output power of photovoltaic modules. The maximum power (Pmax) of a shingled photovoltaic module can be increased by using a bifacial heterojunction with an intrinsic thin layer (HIT) of cells. To fabricate the shingled strings for a high power module, we first cut 6-inch solar cells by laser scribing while minimizing cutting loss. Unlike standard crystalline silicon (c-Si) solar cells, the structure of bifacial HIT solar cells is weak under thermal effect, so an optimal scribing condition had to be found. After laser scribing processes had been optimized, Pmax was increased by 0.02W for each separated solar cells when we using an ultraviolet (UV) laser compared to the green laser, and a UV cut shingled string of HIT cell was demonstrated for the first time.

Poly(fluorene-alt-benzothiadiazole) (PFBT) is a promising chiral polymer for use in metamaterials and other photonic applications, due to its large chiral optical activity at visible wavelengths. However, its usages are very limited, since it is not readily patternable into microstructures and challenging to apply to applications. In this paper, we demonstrate photo patterning of chiral PFBT/Achiral SU-8 photoresist to produce high quality structures while retaining the extraordinary chiral optical activity of our previously-reported PFBT/SU8 nanocomposite films. The ability to produce cleanly patterned microfeatures with high chirality may enable wider use of PFBT in chiral metamaterials and other photonic applications.

Shingled string photovoltaic (PV) cells have a larger active area, and they significantly reduced damage from the interconnection process using electrically conductive adhesives. This new method using a shingled design provides increased PV module power compared with the conventional PV module for the same installed area. In this work, we study the optimization of shingled string PV cells for high-power shingled design modules (SDMs). To successfully fabricate shingled string PV cells and high-power SDMs, we adjusted the overlap width between solar cells and achieve conversion powers of 406.5 W for a 1100 mm × 1980 mm area. Finally, we perform a reliability tests to verify the durability of our SDMs.