Broadband near-infrared (NIR) spectroscopy generated from a phosphor-converted light-emitting diode (pc-LED) has multifunctional applications, including food-quality analysis, bio-medical and night-vision, stimulating the demand for developing various NIR phosphors with desired properties. Herein, we selected a highly distorted garnet CaHfGeO as the host and explored the near-infrared luminescence of Cr. As expected, this material achieved a long-wavelength NIR emission and excellent absorption efficiency based on the effect of Jahn-Teller distortion. The synthesized CaHfGeO:Cr phosphor exhibits a broadband NIR emission peaking at 840 nm with a full width at half maximum of 150 nm, and the absorption efficiency reaches 48.0%. However, the internal quantum efficiency of the 6 mol% Cr-doped sample was measured to be only 35.3% and the integral emission intensity at 373 K kept only 60.1% of the initial intensity. The possible reasons for the unsatisfactory internal quantum efficiency and thermal stability were systematically analyzed, which provided a comprehensive understanding of the relationship between the crystal structure and the luminescent properties of Cr-activated garnet-type phosphors. Nevertheless, the as-prepared NIR pc-LED device exhibits a NIR output of 16.52 mW with a NIR photoelectric conversion efficiency of 5.92% driven by 100 mA current, indicating the potential of this material for application in NIR pc-LED.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1039/d3cp01547e | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
We report a high peak power mid-infrared (MIR) source via efficient optical parametric generation (OPG) in a piece of 50-mm-long MgO: PPLN crystal pumped by using a near-infrared (NIR) narrow-band picosecond laser source. The highest peak power of the idler pulse can reach ∼109.86 kW with a duration of ∼7.
View Article and Find Full Text PDFNext-Generation Ultrafast Photoluminescence Spectroscopy: Integration of Transient Grating Optical Gate and Advanced Femtosecond Laser Technology.
J Phys Chem Lett
January 2025
Robinson Research Institute, Faculty of Engineering, Victoria University of Wellington, Wellington 6012, New Zealand.
We demonstrate a high-performance ultrafast broadband time-resolved photoluminescence (TRPL) system based on the transient grating photoluminescence spectroscopy (TGPLS) technique. The core of the system is a Kerr effect-induced transient grating (TG) optical gate driven by high repetition rate ultrashort laser pulses at 1030 nm with micro-Joule pulse energy. Satisfying the demands of spectroscopy applications, the setup achieves high sensitivity, rapid data acquisition, ultrafast time resolution, and a wide spectral window from ultraviolet to near-infrared.
View Article and Find Full Text PDFArtificial Fine-Tuned van Hove Singularity in Twisted Bilayer and Double-Twist Trilayer Graphene with Enhanced Absorption for Photodetection and Photoemission in the Near-Infrared II Range.
ACS Appl Mater Interfaces
January 2025
State Key Lab of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, Sun Yat-sen University, Guangzhou 510275, China.
Optical responses of twisted bilayer graphene at targeted wavelengths can be amplified by leveraging energy levels of van Hove singularities (VHS) via tuning periods of moiré superlattices. Therefore, precise control of twist angles as well as the moiré superlattices is necessary for fabricating integrated optoelectronic devices such as photodetectors and emitters. Although recent advances in twist angle control help the observation of correlated states in twisted magic-angle graphene structures, the impact of such precise control on enhanced optical absorption is still under investigation.
View Article and Find Full Text PDFMultifunctional applications enabled by tunable multi-emission and ultra-broadband VIS-NIR luminescence energy transfer in Sn/Mn-doped lead-free Zn-based metal halides.
Mater Horiz
January 2025
School of Physical Science and Technology, School of Chemistry and Chemical Engineering, State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures, and School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China.
Metal halides are widely applied in solid-state lighting (SSL), optoelectronic devices, information encryption, and near-infrared (NIR) detection due to their superior photoelectric properties and tunable emission. However, single-component phosphors that can be efficiently excited by light-emitting diode (LED) chips and cover both the visible (VIS) and NIR emission regions are still very rare. To address this issue, (TPA)ZnBr:Sn/Mn (TPA = [(CHCHCH)N]) phosphors were synthesized by using the solvent evaporation method.
View Article and Find Full Text PDFA highly visible-transparent thermochromic smart window with broadband infrared modulation for all-season energy savings.
Natl Sci Rev
February 2025
National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Frontiers Science Center for Critical Earth Material Cycling, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
Thermochromic smart windows effectively reduce the energy consumption for buildings through passive light modulation including the transmission of visible (T) and near-infrared (T) light, and the emissivity of mid-infrared (ε) light in response to ambient temperature change. However, thermochromic windows that maintain high T while modulating T and ε simultaneously are highly desirable but still challenging. Here, we develop a thermochromic smart window based on a two-way shape memory polymer to enable reversible transformation and achieve T modulation of 44.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!