Remote Sensing
·
2021
·Vol. 13
·期 16
·3311
·
IF 4.848
Alejandro Sánchez de Miguel,Jonathan Bennie,Emma Rosenfeld,Simon Dzurjak,Kevin J. Gaston
The global spread of artificial light is eroding the natural night-time environment. The estimation of the pattern and rate of growth of light pollution on multi-decadal scales has nonetheless proven challenging. Here we show that the power of global satellite observable light emissions increased from 1992 to 2017 by at least 49%. We estimate the hidden impact of the transition to solid-state light-emitting diode (LED) technology, which increases emissions at visible wavelengths undetectable to existing satellite sensors, suggesting that the true increase in radiance in the visible spectrum may be as high as globally 270% and 400% on specific regions. These dynamics vary by region, but there is limited evidence that advances in lighting technology have led to decreased emissions.Keywords:ALAN;artificial light at night;astronomy;DMSP;LEDs;light pollution;melatonin;nocturnal ecology;VIIRS
研究领域:
环境科学
·
生物学
✓ 已验证
DOI
高影响因子
Nano Energy
·
2025
·
IF 17.1
Nasrud Din,Fawad Saeed,Sajid Hussain,Rai Muhammad Dawood Sultan,Zhang Yuyi,Premkumar Sellan,Qing Li,Zhiwei Zhao,Zhuoya Zhu,Jianming Zhou,Byung Seong Bae,Damian C. Onwudiwe,Qasim Khan,Zaman Ashraf,Wei Lei
Advanced bioimaging requires a uniform and large-area near-infrared (NIR) light illumination source. Achieving uniform light typically involves the use of inorganic near-infrared light-emitting diodes (NIR-LEDs), such as AlGaAs or GaAs, which are often complemented by additional optical components like reflectors and diffusers. However, the use of such optical components imposes limitations on their applicability and flexibility. On the other hand, Quantum dot NIR LEDs (NIR-QLEDs) offer distinct advantages for bioimaging, as they directly emit light uniformly across their entire surface, without the need for any additional optical components. However, for state-of-the-art quantum dot-based NIR LEDs, the previous NIR-QLEDs have suffered from suboptimal charge transport and rapid degradation, limiting their radiance and EQE. This work addresses these limitations by demonstrating an industrial-friendly, all-solution processing technique for NIR-QLED device fabrication with significantly enhanced radiance and efficiency by utilizing copper (Cu) doped InP/ZnSe quantum dots (QDs). Cu-doping in InP/ZnSe QDs generates localized intra-gap states, enhancing carrier trapping and radiative recombination while suppressing non-radiative pathways, leading to unprecedented NIR peak emission at 924 nm and a narrow full-width at half maximum (FWHM) of 81 nm. These intra-gap states facilitate pure NIR emission, thereby substantially enhancing the device's efficiency. Based on the energy levels of the doped InP/ZnSe quantum dots (QDs), ZnMgO and WO₃ are employed as the electron transport layer (ETL) and hole transport layer (HTL), respectively. ZnMgO and WO₃ provide favorable conduction and valence band offsets, ensuring efficient carrier injection while suppressing leakage currents. The NIR-QLED exhibited an external quantum efficiency (EQE) of approximately 16 %. With a high current density of 250 × 10⁻³ A cm⁻², the radiance improved to 62 W sr⁻¹ m⁻². The all-solution processing technique employed in this work enabled the fabrication of a large emission area measuring 35 mm × 35 mm. Under illumination from this NIR-QLED, subcutaneous deep vein images were clearly observable. Consequently, this all-solution process not only simplifies the production process but also facilitates scalability, paving the robust route for the development of larger-area devices tailored for complex bioimaging applications.
研究领域:
生物医学光学
·
纳米技术
·
材料科学
·
光子学
·
生物成像
·
半导体器件
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry Letters
·
2023
·
IF 5.7
Fei Li,Jiao Jiao Liu,Qiulei Xu,Ruiguang Chang,Lei Wang,Zhenghui Wu,Huaibin Shen,Zuliang Du
PbS quantum dot light-emitting diodes (QLEDs) emitting around 1550 nm promise important applications in optical communications. However, due to insufficient suppression of surface traps for large-size PbS quantum dots (QDs), their performance under large driving current density was not satisfactory. In this work, octanethiol surfactant was added into a PbS QD solution and adsorbed onto the dot surface. As a result, the surface traps and the continuous oxidation of the unprotected (100) facets in PbS QDs were greatly suppressed. Therefore, the PbS QDs with octanethiol doubled their photoluminescence efficiency and showed outstanding stability. The PbS-based QLEDs with benchmark device structure showed a breakthrough high radiance of 18.3 W sr–1 m–2 with >2000 mA/cm2 driving current density. The efficient passivation of surface traps with octanethiol surfactant and the suppressed coupling between excitons and surface states under large working current were the main reasons for achieving the breakthrough high radiance.
研究领域:
纳米技术
·
光电子学
·
材料科学
·
半导体器件
·
量子点
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）