The optoelectronic properties of organic lead halide perovskites (OLHPs) strongly depend on their underlying crystal symmetry and dynamics. Here, we exploit temperature-dependent synchrotron powder X-ray diffraction and temperature-dependent photoluminescence to investigate how the subtle structural changes happening in the pure and mixed A-site cation MAFAPbBr ( = 0, 0.5, and 1) systems influences their optoelectronic properties. Diffraction investigations reveal a cubic structure at high temperatures and tetragonal and orthorhombic structures with octahedral distortion at low temperatures. Steady state photoluminescence and time correlated single photon counting study reveals that the dual emission behavior of these OLHPs is due to the direct-indirect band formation. In the orthorhombic phase of MAPbBr, the indirect band is dominated by self-trapped exciton (STE) emission due to the higher-order lattice distortions of PbBr octahedra. Our findings provide a comprehensive explanation of the dual emission behavior of OLHPs while also providing a rationale for previous experimental observations.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.jpclett.4c00250 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Electromagnetic Radiation and Biophoton Emission in Neuronal Communication and Neurodegenerative Diseases.
Prog Biophys Mol Biol
December 2024
Molecular Biotechnology, Turkish-German University, Sahinkaya Caddesi No. 106, Beykoz, Istanbul 34820 Turkey. Electronic address:
The intersection of electromagnetic radiation and neuronal communication, focusing on the potential role of biophoton emission in brain function and neurodegenerative diseases is an emerging research area. Traditionally, it is believed that neurons encode and communicate information via electrochemical impulses, generating electromagnetic fields detectable by EEG and MEG. Recent discoveries indicate that neurons may also emit biophotons, suggesting an additional communication channel alongside the regular synaptic interactions.
View Article and Find Full Text PDFAn adaptive and lightweight YOLOv5 detection model for lung tumor in PET/CT images.
Sci Rep
December 2024
School of Computer Science and Engineering, North Minzu University, Yinchuan, 750021, China.
Multi-modal medical images are important in tumor lesion detection. However, the existing detection models only use single-modal to detect lesions, a multi-modal semantic correlation is not enough to consider and lacks ability to express the shape, size, and contrast degree features of lesions. A Cross Modal YOLOv5 model (CMYOLOv5) is proposed.
View Article and Find Full Text PDFCerebral Amyloid-β Deposition, Axial Features, and Cognitive Alterations in Patients with Parkinson's Disease Treated with Bilateral STN-DBS: A Long-Term Cohort Study.
J Pers Med
December 2024
Neurology Unit, Neuromotor & Rehabilitation Department, Azienda USL-IRCCS di Reggio Emilia, 42123 Reggio Emilia, Italy.
Our aim was to evaluate the possible long-term cerebral deposition of amyloid-β in patients with PD treated with subthalamic nucleus deep brain stimulation (STN-DBS) and its possible influence on axial and cognitive variables. Consecutive PD patients treated with bilateral STN-DBS with a long-term follow-up were included. The amyloid-β deposition was evaluated postoperatively through an 18F-flutemetamol positron emission tomography (PET) study.
View Article and Find Full Text PDFAn Evaluation of 90Y Bremsstrahlung SPECT Image Quality in the Presence of 99mTc: A Technical Perspective on Same-Day Radioembolization.
Curr Oncol
November 2024
Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands.
In same-day radioembolization, 99mTc-MAA SPECT/CT, 90Y radioembolization, and post-treatment 90Y SPECT/CT procedures are conducted on the same-day, resulting in a dual-isotope environment of 90Y and 99mTc during post-treatment imaging. This study aimed to quantify the impact of 99mTc on 90Y bremsstrahlung-SPECT/CT image quality and to establish an optimised imaging protocol for both clinical practice, and with advanced reconstruction techniques. Utilising a NEMA IQ phantom, contrast recovery coefficients (CRCs) were measured to evaluate the 90Y image quality degradation caused by 99mTc.
View Article and Find Full Text PDFFacile Hydrothermal Assisted Basic Catalyzed Sol Gel Synthesis for Mesoporous Silica Nanoparticle from Alkali Silicate Solutions Using Dual Structural Templates.
Gels
December 2024
Chemistry Department, Faculty of Science, Taibah University, Medina Munwarah 42353, Saudi Arabia.
This work presents a novel hydrothermally aided sol-gel method for preparation of mesoporous silica nanoparticles (MSNs) with a narrow particle size distribution and varied pore sizes. The method was carried out in alkaline media in presence of polyethylene glycol (PEG) and cetyltrimethylammonium chloride (CTAC) as dual templates and permitted the synthesis of spherical mesoporous silica with a high surface area (1011.42 m/g).
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!