Heterovalent CsPbBr doping with Bi results in a significant red shift of the optical absorption of both single-crystal and powdered samples. The results of low-temperature (3.6 K) photoluminescence studies of perovskite single crystals indicate that the position of the excitonic luminescence peak remains unaffected by Bi doping that, in turn, infers that the band gap of Bi-doped perovskite is not changed as well. The position and state density distribution of the valence band and Fermi level of single-crystal perovskites were determined by another direct method of ultraviolet photoelectron spectroscopy. The obtained results show that Bi doping causes no changes in the valence band structure but an increase in the Fermi level by 0.6 eV. The summary of the obtained results directly demonstrates that the concept of the band-gap engineering in Bi-doped CsPbBr halide perovskite is not valid.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.jpclett.8b02178 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Towards all inorganic antimony sulphide semitransparent solar cells.
Sci Rep
January 2025
Laboratory for Thin Film Energy Materials, Department of Materials and Environmental Technology, School of Engineering, Tallinn University of Technology, Ehitajate tee 5, Tallinn, 19086, Estonia.
NiO, a wide band gap hole-transporting material (HTM), is gaining attention in photovoltaics due to its optical transparency, chemical stability, and favourable band alignment with absorber. This study uses NiO nanoparticle-based HTM in semi-transparent SbS solar cells via a simple chemical precipitation method. We optimised NiO layer by varying precursor solution concentration and studied its impact on optical and structural properties, composition of nanoparticles and subsequent effect on the performance of semi-transparent SbS solar cell.
View Article and Find Full Text PDFIn situ self-cleaning removal of emerging organic contaminants with covalent organic framework armed with arylbiguanide.
J Hazard Mater
January 2025
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China; The Key Laboratory of Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875, PR China. Electronic address:
An in situ self-cleaning covalent organic framework featuring arylbiguanide arms (Aryl-BIG-COF) was first developed to remove emerging organic pollutants such as propranolol (PRO) from water. The main breakthroughs addressed the scarcity of functional active sites, the impracticality of ex situ regeneration, and the rapid recombination of electronhole pairs in the application of COFs. Owing to the directional capture ability and electronic structure regulation of the arylbiguanide arms, the adsorption capacity and photocatalytic degradation rate of the newly synthesized COF increased by nearly four and seven times, respectively.
View Article and Find Full Text PDFDoubly Linked Azulene Dimer: A Novel Non-benzenoid Isomer of Perylene.
Chemistry
January 2025
Yamaguchi University, Department of Chemistry, 753-8512, Yamaguchi, JAPAN.
We report herein the synthesis of an unprecedented isomer of perylene, dicyclohepta[cd,fg]-as-indacene bearing two phenyl groups (1-Ph) by the nickel-mediated intramolecular homocoupling of a 4,4'-biazulene derivative (2). The X-ray crystallographic analysis and theoretical calculations revealed that 1-Ph adopts a unique helically twisted geometry although the local aromaticity of azulene moieties was preserved. The double covalent linkage of the two azulene skeletons imparts significant orbital interaction, which affords near-infrared (NIR) absorption (up to 1720 nm) and remarkable redox behaviors despite its closed-shell electronic structure.
View Article and Find Full Text PDFAttoampere Level Leakage Current in Chemical Vapor Deposition-Grown Monolayer MoS Dynamic Random-Access Memory in Trap-Assisted Tunneling Limit.
ACS Nano
January 2025
BK21 Graduate Program in Intelligent Semiconductor Technology, Seoul 03722, Republic of Korea.
MoS, one of the most researched two-dimensional semiconductor materials, has great potential as the channel material in dynamic random-access memory (DRAM) due to the low leakage current inherited from the atomically thin thickness, high band gap, and heavy effective mass. In this work, we fabricate one-transistor-one-capacitor (1T1C) DRAM using chemical vapor deposition (CVD)-grown monolayer (ML) MoS in large area and confirm the ultralow leakage current of approximately 10 A/μm, significantly lower than the previous report (10 A/μm) in two-transistor-zero-capacitor (2T0C) DRAM based on a few-layer MoS flake. Through rigorous analysis of leakage current considering thermionic emission, tunneling at the source/drain, Shockley-Read-Hall recombination, and trap-assisted tunneling (TAT) current, the TAT current is identified as the primary source of leakage current.
View Article and Find Full Text PDFElectromagnetic and optical properties of Na, Mg, and Al-adsorbed stanene nanoribbons: potential applications.
J Phys Condens Matter
January 2025
Institute for Southeast Regional Development Studies, Thu Dau Mot University, Thu Dau Mot City, Binh Duong Province, Vietnam.
Density functional theory (DFT) combined with the Viennasimulation package (VASP) was used to investigate the electronic, magnetic, and optical properties of one-dimensional stanene nanoribbons (SnNRs) and Na, Mg, and Al-adsorbed SnNRs. The SnNRs, with a width of 10 Sn atoms and hydrogen-passivated edges, retained their hexagonal honeycomb structure after structural optimization. Both pristine and adsorbed SnNRs exhibit narrow band gap semiconducting behavior, with pristine SnNRs being non-magnetic and adsorbed SnNRs showing non-zero magnetic moments.
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!