A strategy for increasing the conversion efficiency of organic photovoltaics has been to increase the VOC by tuning the energy levels of donor and acceptor components. However, this opens up a new loss pathway from an interfacial charge transfer state to a triplet exciton (TE) state called electron back transfer (EBT), which is detrimental to device performance. To test this hypothesis, we study triplet formation in the high performing PTB7:PC71BM blend system and determine the impact of the morphology-optimizing additive 1,8-diiodoctane (DIO). Using photoluminescence and spin-sensitive optically detected magnetic resonance (ODMR) measurements at low temperature, we find that TEs form on PC71BM via intersystem crossing from singlet excitons and on PTB7 via EBT mechanism. For DIO blends with smaller fullerene domains, an increased density of PTB7 TEs is observed. The EBT process is found to be significant only at very low temperature. At 300 K, no triplets are detected via ODMR, and electrically detected magnetic resonance on optimized solar cells indicates that TEs are only present on the fullerenes. We conclude that in PTB7:PC71BM devices, TE formation via EBT is impacted by fullerene domain size at low temperature, but at room temperature, EBT does not represent a dominant loss pathway.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4933975 | PMC |
| http://dx.doi.org/10.1038/srep29158 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Physical activity during summer and recognition of heatstroke prevention among patients with cardiovascular disease in an urban area of Japan: a descriptive study.
BMC Res Notes
January 2025
Department of Cardiology, Nagoya Ekisaikai Hospital, Nagoya, Japan.
Objective: Patients with cardiovascular disease are considered a high-risk population for heat-related illnesses. This study aimed to describe the difference in physical activity between summer and fall among patients with cardiovascular disease and their recognition of heatstroke prevention in an urban area with high temperature conditions.
Results: We enrolled 56 outpatients who participated in cardiac rehabilitation in the summer of 2022 (median age, 75 years [interquartile range, 68-80]).
Atmospheric cold plasma alters plant traits and negatively affects the growth and development of fall armyworm in rice.
Sci Rep
January 2025
Department of Entomology and Plant Pathology, University of Arkansas, Fayetteville, AR, 72701, USA.
Plasma is considered as the fourth state of matter, and atmospheric cold plasma (cold plasma) is a type of plasma consisting of ionized gases containing excited species of atoms, molecules, ions, and free radicals at near room temperature. Cold plasma is generated by applying high voltage to gases, causing it to ionize thus forming plasma. Although cold plasma has been found to break seed dormancy and improve germination rate, only a few studies have explored the potential of cold plasma against insect herbivory.
View Article and Find Full Text PDFThermostable terahertz metasurface enabled by graphene assembly film for plasmon-induced transparency.
Sci Rep
January 2025
State Key Laboratory of New Textile Materials and Advanced Processing Technologies, Wuhan Textile University, Wuhan, 430200, People's Republic of China.
With the increasing demand on high-density integration and better performance of micro-nano optoelectronic devices, the operation temperatures are expected to significantly increase under some extreme conditions, posing a risk of degradation to metal-based micro-/nano-structured metasurfaces due to their low tolerance to high temperature. Therefore, it is urgent to find new materials with high-conductivity and excellent high-temperature resistance to replace traditional micro-nano metal structures. Herein, we have proposed and fabricated a thermally stable graphene assembly film (GAF), which is calcined at ultra-high temperature (~ 3000 ℃) during the reduction of graphite oxide (GO).
View Article and Find Full Text PDFEcofriendly remediation of cadmium, lead, and zinc using dead cells of Microcystis aeruginosa.
Sci Rep
January 2025
Hydrobiology Lab, National Institute of Oceanography and Fisheries (NIOF), Cairo, Egypt.
The utilization of cyanobacteria toxin-producing blooms for metal ions adsorption has garnered significant attention over the last decade. This study investigates the efficacy of dead cells from Microcystis aeruginosa blooms, collected from agricultural drainage water reservoir, in removing of cadmium, lead, and zinc ions from aqueous solutions, and simultaneously addressing the mitigation of toxin-producing M. aeruginosa bloom.
View Article and Find Full Text PDFConvergent evidence for the temperature-dependent emergence of silicification in terrestrial plants.
Nat Commun
January 2025
Ministry of Education Key Laboratory of Environment Remediation and Ecological Health, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, 310058, China.
Research on silicon (Si) biogeochemistry and its beneficial effects for plants has received significant attention over several decades, but the reasons for the emergence of high-Si plants remain unclear. Here, we combine experimentation, field studies and analysis of existing databases to test the role of temperature on the expression and emergence of silicification in terrestrial plants. We first show that Si is beneficial for rice under high temperature (40 °C), but harmful under low temperature (0 °C), whilst a 2 °C increase results in a 37% increase in leaf Si concentrations.
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!