The influence of the growth parameters on the photoluminescence (PL) spectra has been investigated for samples with columnar morphology, either with InN columns on original substrates or as free-standing nanowires. Valuable information about band gap and electron concentration was obtained by line shape analysis. Optical band gaps between 730 and 750 meV and electron concentrations of 8 x 10(17) to 6 x 10(18) cm(-3) were derived from the fit of the PL spectra of different samples. The crystalline quality of the wires was investigated by high-resolution transmission electron microscopy.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/nl060547x | DOI Listing |
Nat Commun
January 2025
State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, P. R. China.
Photoluminescence is one of the most intriguing properties of metal nanoclusters derived from their molecular-like electronic structure, however, achieving high photoluminescence quantum yield (PLQY) of metal core-dictated fluorescence remains a formidable challenge. Here, we report efficient suppression of the total structural vibrations and rotations, and management of the pathways and rates of the electron transfer dynamics to boost a near-unity absolute PLQY, by decorating progressive addition of cations. Specifically, with the sequential addition of Zn, Ag, and Tb into the 3-mercaptopropionic acids capped Au nanoclusters (NCs), the low-frequency vibration of the metal core progressively decreases from 144.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
Molecular Materials and Nanosystems & Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
Reducing nonradiative recombination is crucial for minimizing voltage losses in metal-halide perovskite solar cells and achieving high power conversion efficiencies. Photoluminescence spectroscopy on complete or partial perovskite solar cell stacks is often used to quantify and disentangle bulk and interface contributions to nonradiative losses. Accurately determining the intrinsic loss in a perovskite layer is key to analyzing the origins of nonradiative recombination and developing defect engineering strategies.
View Article and Find Full Text PDFSci Rep
January 2025
School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
Nanoscale Fourier transform infrared (Nano-FTIR) imaging and spectroscopy correlated with photoluminescence measurements of lunar Apollo samples with different surface radiation exposure histories reveal distinct physical and chemical differences associated with space weathering effects. Analysis of two sample fragments: an ilmenite basalt (12016) and an impact melt breccia (15445) show evidence of intrinsic or delivered Nd and an amorphous silica glass component on exterior surfaces, whereas intrinsic Cr and/or trapped electron states are limited to interior surfaces. Spatially localized 1050 cm/935 cm band ratios in Nano-FTIR hyperspectral maps may further reflect impact-induced shock nanostructures, while shifts in silicate band positions indicate accumulated radiation damage at the nanoscale from prolonged space weathering due to micrometeorites, solar wind, energetic x-rays and cosmic ray bombardment.
View Article and Find Full Text PDFLangmuir
January 2025
Key Laboratory of Photonic Materials and Devices Physics for Oceanic Applications, Ministry of Industry and Information Technology of China, College of Physics and Optoelectronic Engineering, Harbin Engineering University, Harbin 150001, China.
Due to intrinsic defects in blue-light-emitting perovskite materials, the charge carriers are prone to being trapped by the trap states. Therefore, the preparation of efficient blue-light-emitting perovskite materials remains a significant challenge. Herein, CsPb(Cl/Br) nanocrystal (NCs)@SiO structures were fabricated through hydrolyzing (3-aminopropyl)-triethoxysilane (APTS).
View Article and Find Full Text PDFJ Phys Chem B
January 2025
Science and Technology on Aerospace Chemical Power Laboratory, Laboratory of Emergency Safety and Rescue Technology, Hubei Institute of Aerospace Chemotechnology, Xiangyang 441003, China.
Doped semiconductors are often used to improve photocatalytic efficiency and address the challenges of easy recombination of electron-hole pairs and poor photoluminescence. However, the reproducibility and complexity of experimental studies result in time-consuming and less cost-effective studies, and it is difficult to gain insights into the intrinsic properties of doped photocatalysts to control their performance. Introducing a machine learning approach, we constructed a photocatalytic model of transition-metal- and rare earth metal-ion-doped γ-BiMoO.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!