Considering the multi-functionalization of ligands, it is crucial for ligand molecular design to reveal the landscape of anchoring sites. Here, a typical triphenylphosphine (TPP) ligand was employed to explore its effect on the surface of CsPbI 3 perovskite nanocrystals (PNCs). Except for the conventionally considered P-Pb coordination, an P-I supramolecular halogen bonding was also found on the NC surface. The coexistence of the above two types of bonding significantly increased the formation energy of iodine vacancy defects and improved the photoluminescence quantum yield of PNCs up to 93%. Meanwhile, the direct interaction of P and I enhanced the stability of the Pb-I octahedra and dramatically inhibited the migration of I ions. Furthermore, the introduction of additional benzene rings (2-(Diphenylphosphino)-biphenyl (DPB)) increased the delocalized properties of the PNC surface and significantly improved the charge transport of the PNCs. As a result, the DPB passivated CsPbI 3 NCs based top-emitting LEDs exhibite a peak external quantum efficiency (EQE) of 22.8%, a maximum luminance of 15, 204 cd m −2 , and an extremely low-efficiency roll-off of 2.6% at the current density of 500 mA cm −2 .

随着国家碳中和、碳达标战略和政策的实施,本文探讨城市道路隧道节能和安全照明的应用研究.通过一体化热传输技术,多自由曲面逐点精准配光设计和全自动过盈配合快速精准装配技术,实现单光源可调色温LED产品设计及产业化示范应用,提升城市隧道照明整体技术水平和节能功效,开发多色温LED智能调光系统,提升隧道照明舒适度,降低驾驶疲劳感,提高行车安全性和道路通行率,满足智慧交通和数字城市的建设需要.

黑板照明是影响课堂教学质量的关键因素之一,黑板照明产品光学设计是保证黑板照明质量的先决条件,标准严格的安装要求也是实现最终设计的重要闭环,因此从设计、选型、工艺、安装及测试验收全链条的把控才能保障高质量黑板照明的成功应用.本文结合以上影响因素及市场产品现状,模拟和分析不同因素对讲台区域照明光品质和光健康的影响,提出一种基于复合型非对称主动偏光设计的黑板照明策略,为照明设计师和终端应用客户提供设计建议,为儿童青少年视力健康保驾护航.

With the rapid development of social science, technology and economy, the attention of domestic classroom healthy lighting light environment continues to rise. At present, there is insufficient in-depth research on the lighting light quality and light health of the research area. The paper takes the blackboard lighting quality and the visual comfort of teachers and students as the research object. We summarize and analyze the current blackboard lighting products, and put forward lighting design suggestions to help children and adolescents' vision health.

Based on the current classroom lighting standards, specifications and requirements, the classroom light health indicators are sorted out. We investigate the current classroom lighting environment in primary and secondary schools and rectify the design of light environment to improve visual health and comfort. Finally, we propose a design strategy for the health light environment in classroom.

基于现行教室照明标准、 规范及要求,梳理了教室光健康指标,调研了目前中小学教室照明光环境并进行整改设计,为了提高视觉健康度和舒适度,提出了面向教室健康光环境的照明设计策略.

以经过全新照明改造的一汽红旗M焊装车间为例,基于GB/T 51268-2017《绿色照明检测及评价标准》,设计针对工业厂房照明环境的评分系统进行照明质量的检测及评价,并通过主观问卷形式对员工所处光环境的视觉舒适度、视觉执行度和视觉氛围性进行调研,总结目前工业厂房在采光、照明方面存在的问题,为后期工业厂房光环境优化设计研究提供参考,并提出了LED大空间工业照明设计的建议.

研究表明,0～3岁是婴幼儿身体和视力发育速度最快的阶段,也是晶状体和视网膜最脆弱的时期,因此合理设计适用于婴幼儿的健康光环境具有重要的意义和价值.本文结合婴幼儿潜在的视觉感知和个性偏好,分析其心理和生理发育规律,从光对婴幼儿视觉和非视觉两个方面的影响进行综述,尝试建立有利于婴幼儿的舒适健康光环境系统.

The bandwidth of white light emitting diodes (WLEDs) is an important factor that affects most of the system performances in visible light communication (VLC). It is mainly limited by the down-conversion phosphors. We propose in this paper to employ nanomaterial phosphors with short fluorescence lifetime and high quantum yield in VLC. The white-emitting device of bandwidth-based lifetime was fabricated by using several kinds of nanophosphors with different fluorescence lifetimes. Moreover, we proposed two theoretical models to analyze the factors that affect bandwidth. Compared with the commercial YAG-based WLEDs, the bandwidth of nanophosphor-based WLEDs can be improved over three times and close to the blue excitation sources. Our study indicates that nanophosphors can become promising fluorescent materials in VLC, and provides a new direction for developing wide-bandwidth VLC systems.

In recent years, quantum dots (QDs) have been widely studied because of their precisely tunable, narrow, and strong emission. Different kinds of light-emitting diodes (LEDs) have been fabricated by QDs, and it is desirable to utilize QD-LEDs to form the next-generation display. Here, we review a few key technologies in the area of QD-LED displays, including the compositions and the structures of the QDs, the methods of forming QD layers, and the architectures, crosstalk, and encapsulations of the QD-LEDs.

Quantum dot white light-emitting diodes (QD-WLEDs) were fabricated from green- and red-emitting AgInS2/ZnS core/shell QDs coated on GaN LEDs. Their electroluminescence (EL) spectra were measured at different currents, ranging from 50 mA to 400 mA, and showed good color stability. The modulation bandwidth of previously prepared QD-WLEDs was confirmed to be much wider than that of YAG:Ce phosphor-based WLEDs. These results indicate that the AgInS2/ZnS core/shell QDs are good color-converting materials for WLEDs and they are capable in visible light communication (VLC).

WLEDs were fabricated with commendable color rendering index, widely variable color temperatures and high luminous efficacy by combining green and red emitting polymer dots on YAG:Ce-based WLEDs.

A white light-emitting diode (0.33, 0.33) is fabricated using perovskite quantum dot/silica composites. It is shown to have greatly improved stability.

The quantum dot-based light-emitting diodes (QD-LEDs) were fabricated using blue GaN chips and red-, yellow-, and green-emitting ZnCuInS/ZnSe/ZnS QDs. The power efficiencies were measured as 14.0 lm/W for red, 47.1 lm/W for yellow, and 62.4 lm/W for green LEDs at 2.6 V. The temperature effect of ZnCuInS/ZnSe/ZnS QDs on these LEDs was investigated using CIE chromaticity coordinates, spectral wavelength, full width at half maximum (FWHM), and power efficiency (PE). The thermal quenching induced by the increased surface temperature of the device was confirmed to be one of the important factors to decrease power efficiencies while the CIE chromaticity coordinates changed little due to the low emission temperature coefficients of 0.022, 0.050, and 0.068 nm/°C for red-, yellow-, and green-emitting ZnCuInS/ZnSe/ZnS QDs. These indicate that ZnCuInS/ZnSe/ZnS QDs are more suitable for downconversion LEDs compared to CdSe QDs.