Latest news with #InternationalSocietyforOpticsandPhotonics
Yahoo
03-05-2025
- Science
- Yahoo
Ultra-high efficiency achieved in silicon solar panels with new, smart nanostructural layer
Scientists have achieved high efficiency in silicon solar cells with the help of precision-engineered surfaces. New designs of antireflective coatings for silicon solar cells, based on single-layer silicon metasurfaces, lead to broadband reflection suppression in the wavelength range from 500 to 1200 nm for incidence angles up to 60 have highlighted that the conventional few-layer dielectric antireflective coatings may significantly boost the transmission of solar light, but only in a narrow wavelength range. The latest research took place as almost half of the solar energy that reaches a silicon solar cell is lost due to the reflection at the silicon–air interface. While antireflective coatings can suppress the reflection and increase the photogenerated study by SPIE-the International Society for Optics and Photonics, reveals a new type of antireflective coating using a single, ultrathin layer of polycrystalline silicon nanostructures (a.k.a., a metasurface).Achieving minimal reflection across certain wavelengths and angles, the metasurface was reportedly developed by combining forward and inverse design techniques, enhanced by artificial intelligence (AI).Published in Advanced Photonics Nexus, the study reveals that the reflection averaged over the visible and near-infrared spectra is at the record-low level of approximately 2% and 4.4% for the normal and oblique incidence, respectively."The obtained results demonstrate the potential of machine learning–enhanced photonic nanostructures to outperform the classical antireflective coatings," said researchers. They revealed that the coating works across the visible and near-infrared spectrum (500 to 1200 nanometers) and is effective even when the sunlight hits at steep angles. It reflects as little as 2 percent of incoming light at direct angles and about 4.4 percent at oblique angles—unprecedented results for a single-layer breakthrough shows that an intelligently designed nanostructural layer can boost the efficiency of mainstream solar panels. Because it is both high-performing and relatively simple, it could lead to more efficient solar panels, potentially speeding up the transition to clean energy, according to a press release. Researchers also stressed that beyond solar energy, the approach also advances how scientists design metasurfaces for optics and photonics. It opens the door to multifunctional photonic coatings that could benefit not just solar power but also sensors and other optical devices. They underlined that the proposed metasurface-enhanced solutions demonstrate high functionality in terms of the reflection reduction with ARCs on glass and other low-index substrates. The study reveals that the forward design can produce very promising results given the appropriate choice of geometric parameters, whereas when using the inverse design approach, one does not have to settle on a geometry type in advance and be reasonably confident that the solution would be close to the global optimum. "We have managed to obtain both forward-designed cross-circular and free-form inverse-designed structures with the best reported antireflection properties for single-layer structures," said researchers in the study.
Yahoo
25-03-2025
- Science
- Yahoo
China's breakthrough solid-state deep ultraviolet laser could transform chipmaking
Scientists from the Chinese Academy of Sciences (CAS) have reportedly made a major 'breakthrough' in solid-state deep ultraviolet (DUV) lasers. A paper published in a journal by International Society for Optics and Photonics (SPIE) has revealed that researchers from China have created a coherent 193 nm (nanometer) beam used for semiconductor photolithography. If scaled up, the new technology could be used to build lithography tools that make chips using advanced process mechanisms. At present, advanced semiconductor chips used in many electronics (like cellphones, computers, etc.) heavily rely on photolithography to work. This process involves etching patterns onto silicon wafers using special ultraviolet (UV) lasers. The industry standard for DUV lithography uses a 193 nm wavelength of UV light produced by gas-based excimer lasers. Now, researchers at the CAS claim they've successfully demonstrated an experimental solid-state laser system that emits this crucial wavelength without using gases. Smaller wavelengths can produce finer and more precise patterns. The 193 nm resolution is critical because it is ideal for making high-performance semiconductor chips. It is also the reason why semiconductor lithography machines by companies like ASML, Canon, and Nikon rely on this exact wavelength. Lithography machines generally use a mixture of Argon (Ar), Fluorine (F), and Neon (Ne) gases inside a sealed laser chamber to function. When functional, a high-voltage pulse excites these gases, briefly creating a short-lived Argon Fluoride (ArF) molecule (an 'excimer'). The excited ArF molecule quickly returns to its stable state, emitting a UV photon at exactly 193 nm wavelength. The pulses delivered by lasers are powerful, typically clocking around 100–120 Watts, at 8–9 kHz frequency. While these gas lasers are reliable and widely used, they're complicated and expensive, requiring careful handling of toxic gases like fluorine. On the other hand, the new CAS laser is a fully solid-state laser, requiring no gas and only employing crystals and optics. The team achieved this by using a Yb:YAG crystal amplifier to generate infrared laser light at 1030 nm wavelength. This beam is then split in two using nonlinear optics to produce a 258 nm beam through Fourth-Harmonic Generation (FHG). Another portion of the 1030 nm beam creates a different wavelength (1553 nm) via an optical parametric amplifier (OPA). The two wavelengths are combined using special nonlinear crystals (cascaded Lithium Triborate or LBO crystals) to produce a coherent beam at 193 nm wavelength. Solid-state means fewer toxic chemicals, no fluorine gas, safer operation, lower operational complexity, and possibly lower maintenance requirements. In general, solid-state lasers tend to be more compact and reliable. However, there are certain downsides, the CAS laser's power is only 70 mW, compared to the 100–120 Watts from commercial excimer lasers. This is several hundred times weaker, making it unsuitable for mass semiconductor production at its present state. The new laser is still in the early experimental phase. Scaling it up or increasing its power output to match current commercial lasers is a significant engineering challenge that might require years or multiple generations of technological refinement. Hence, for now, significant technological hurdles remain, primarily around achieving higher power outputs and maintaining long-term reliability at industrial scales. Findings of the research have been published in the SPIE affiliated journal Advanced Photonics Nexus.
