Alzheimer’s disease (AD) is an age-related neurodegenerative disorder that poses a significant burden on socio-economic and healthcare systems worldwide. However, the currently available therapy of AD is limited, and new strategies are needed to enhance the clearance of β-amyloid (Aβ) protein and improve cognitive function. Photobiomodulation (PBM) is a noninvasive and effective therapeutic method that has shown promise in treating various brain diseases. Here, we demonstrate that 1267-nm PBM significantly alleviates cognitive decline in the 5xFAD mouse model of AD and is safe as it does not induce a significant increase in cortical temperature. Moreover, with the combination of 3D tissue optical clearing imaging and automatic brain region segmentation, we show that PBM-mediated reductions of Aβ plaques in different subregions of prefrontal cortex and the hippocampus are different. The PBM-induced lymphatic clearance of Aβ from the brain is associated with improvement of memory and cognitive functions in 5xFAD mice. Our results suggest that the modulation of meningeal lymphatic vessels (MLVs) should play an important role in promoting Aβ clearance. Collectively, this pilot study demonstrates that PBM can safely accelerate lymphatic clearance of Aβ from the brain of 5xFAD mice, promoting improvement of neurocognitive status of AD animals suggesting that PBM can be an effective and bedside therapy for AD.

Silicon sub-bandgap photodetectors can detect light at the infrared telecommunication wavelengths but with relatively weak photo-response. In this work, we demonstrate the enhancement of sub-bandgap photodetection in silicon by helium-ion implantation, without affecting the transparency that is an important beneficial feature of this type of photodetectors. With an implantation dose of 1 × 10¹³ ions/cm², the minimal detectable optical power can be improved from – 33.2 to – 63.1 dBm, or, by 29.9 dB, at the wavelength of 1550 nm, and the photo-response at the same optical power (– 10 dBm) can be enhanced by approximately 18.8 dB. Our work provides a method for strategically modifying the intrinsic trade-off between transparency and strong photo-responses of this type of photodetectors.

Although perovskite light-emitting diodes (PeLEDs) have seen unprecedented development in device efficiency over the past decade, they suffer significantly from poor operational stability. This is especially true for blue PeLEDs, whose operational lifetime remains orders of magnitude behind their green and red counterparts. Here, we systematically investigate this efficiency-stability discrepancy in a series of green- to blue-emitting PeLEDs based on mixed Br/Cl-perovskites. We find that chloride incorporation, while having only a limited impact on efficiency, detrimentally affects device stability even in small amounts. Device lifetime drops exponentially with increasing Cl-content, accompanied by an increased rate of change in electrical properties during operation. We ascribe this phenomenon to an increased mobility of halogen ions in the mixed-halide lattice due to an increased chemically and structurally disordered landscape with reduced migration barriers. Our results indicate that the stability enhancement for PeLEDs might require different strategies from those used for improving efficiency.

The development of super-resolution technology has made it possible to investigate the ultrastructure of intracellular organelles by fluorescence microscopy, which has greatly facilitated the development of life sciences and biomedicine. To realize super-resolution imaging of living cells, both advanced imaging systems and excellent fluorescent probes are required. Traditional fluorescent probes have good availability, but that is not the case for probes for live-cell super-resolution imaging. In this review, we first introduce the principles of various super-resolution technologies and their probe requirements, then summarize the existing designs and delivery strategies of super-resolution probes for live-cell imaging, and finally provide a brief conclusion and overview of the future.

Controllable fabrication of surface micro/nano structures is the key to realizing surface functionalization for various applications. As a versatile approach, ultrafast laser ablation has been widely studied for surface micro/nano structuring. Increasing research efforts in this field have been devoted to gaining more control over the fabrication processes to meet the increasing need for creation of complex structures. In this paper, we focus on the in-situ deposition process following the plasma formation under ultrafast laser ablation. From an overview perspective, we firstly summarize the different roles that plasma plumes, from pulsed laser ablation of solids, play in different laser processing approaches. Then, the distinctive in-situ deposition process within surface micro/nano structuring is highlighted. Our experimental work demonstrated that the in-situ deposition during ultrafast laser surface structuring can be controlled as a localized micro-additive process to pile up secondary ordered structures, through which a unique kind of hierarchical structure with fort-like bodies sitting on top of micro cone arrays were fabricated as a showcase. The revealed laser-matter interaction mechanism can be inspiring for the development of new ultrafast laser fabrication approaches, adding a new dimension and more flexibility in controlling the fabrication of functional surface micro/nano structures.

Infrared solar cells are more effective than normal bandgap solar cells at reducing the spectral loss in the near-infrared region, thus also at broadening the absorption spectra and improving power conversion efficiency. PbS colloidal quantum dots (QDs) with tunable bandgap are ideal infrared photovoltaic materials. However, QD solar cell production suffers from small-area-based spin-coating fabrication methods and unstable QD ink. Herein, the QD ink stability mechanism was fully investigated according to Lewis acid–base theory and colloid stability theory. We further studied a mixed solvent system using dimethylformamide and butylamine, compatible with the scalable manufacture of method-blade coating. Based on the ink system, 100 cm² of uniform and dense near-infrared PbS QDs (∼ 0.96 eV) film was successfully prepared by blade coating. The average efficiencies of above absorber-based devices reached 11.14% under AM1.5G illumination, and the 800 nm-filtered efficiency achieved 4.28%. Both were the top values among blade coating method based devices. The newly developed ink showed excellent stability, and the device performance based on the ink stored for 7 h was similar to that of fresh ink. The matched solvent system for stable PbS QD ink represents a crucial step toward large area blade coating photoelectric devices.

Lead selenide (PbSe) colloidal quantum dots (CQDs) are suitable for the development of the next-generation of photovoltaics (PVs) because of efficient multiple-exciton generation and strong charge coupling ability. To date, the reported high-efficient PbSe CQD PVs use spin-coated zinc oxide (ZnO) as the electron transport layer (ETL). However, it is found that the surface defects of ZnO present a difficulty in completion of passivation, and this impedes the continuous progress of devices. To address this disadvantage, fluoride (F) anions are employed for the surface passivation of ZnO through a chemical bath deposition method (CBD). The F-passivated ZnO ETL possesses decreased densities of oxygen vacancy and a favorable band alignment. Benefiting from these improvements, PbSe CQD PVs report an efficiency of 10.04%, comparatively 9.4% higher than that of devices using sol-gel (SG) ZnO as ETL. We are optimistic that this interface passivation strategy has great potential in the development of solution-processed CQD optoelectronic devices.

With the increase in the aging population, the global number of people with Alzheimer’s disease (AD) progressively increased worldwide. The situation is aggravated by the fact that there is no the effective pharmacological therapy of AD. Photobiomodulation (PBM) is non-pharmacological approach that has shown very promising results in the therapy of AD in pilot clinical and animal studies. However, the mechanisms of therapeutic effects of PBM for AD are poorly understood. In this study on mice, we demonstrate that photodynamic effects of 5-aminolevulenic acid and laser 635 nm cause reduction of network of the meningeal lymphatic vessels (MLVs) leading to suppression of lymphatic removal of beta-amyloid (Aβ) from the right lateral ventricle and the hippocampus. Using the original protocol of PBM under electroencephalographic monitoring of wakefulness and sleep stages in non-anesthetized mice, we discover that the 7-day course of PBM during deep sleep vs. wakefulness provides better restoration of clearance of Aβ from the ventricular system of the brain and the hippocampus. Our results shed light on the mechanism of PBM and show the stimulating effects of PBM on the brain lymphatic drainage that promotes transport of Aβ via the lymphatic pathway. The effects of PBM on the brain lymphatics in sleeping brain open a new niche in the study of restorative functions of sleep as well as it is an important informative platform for the development of innovative smart sleep technologies for the therapy of AD.

An optical phased array (OPA) is a promising non-mechanical technique for beam steering in solid-state light detection and ranging systems. The performance of the OPA largely depends on the phase shifter, which affects power consumption, insertion loss, modulation speed, and footprint. However, for a thermo-optic phase shifter, achieving good performance in all aspects is challenging due to trade-offs among these aspects. In this work, we propose and demonstrate two types of energy-efficient optical phase shifters that overcome these trade-offs and achieve a well-balanced performance in all aspects. Additionally, the proposed round-spiral phase shifter is robust in fabrication and fully compatible with deep ultraviolet (DUV) processes, making it an ideal building block for large-scale photonic integrated circuits (PICs). Using the high-performance phase shifter, we propose a periodic OPA with low power consumption, whose maximum electric power consumption within the field of view is only 0.33 W. Moreover, we designed Gaussian power distribution in both the azimuthal (ϕ) and polar (θ) directions and experimentally achieved a large sidelobe suppression ratio of 15.1 and 25 dB, respectively.