405905 research outputs found
Sort by
Optimizing the methanol-to-Gasoline Reactor: Application of Response Surface Methodology
No full textZnO quantum dots as an electron-transport layer for highly efficient and stable organic solar cells
No full textAn advanced protocol for the mild synthesis of stable and concentrated ZnO quantum dots (QDs) yields colloidal inks suitable for applications in electron-transport layers (ETLs) of organic solar cells, delivering superior power conversion efficiency (PCE) and photodegradation stability as compared to bulk-like commercially available ZnO inks. The champion ZnO QDs-based devices with a quaternary PM6 : L8BO : BTP-eC9 : PC70BM absorber exhibit a PCE of 18.86%, surpassing similar cells with bulk-like ZnO ETL (18.15%). The ZnO QDs exhibited size-dependent electron-transport efficiency, with the highest performance achieved for QDs of 4.4–4.5 nm, decreasing for larger QDs down to the level of the bulk-like ZnO reference. A correlation between the photoluminescence and electron-transport efficiencies of ZnO quantum dots (QDs) was observed and interpreted in terms of an interplay between the defect state density and exciton confinement in size-selected ZnO QDs
Locating the non-radiative recombination losses of perovskite solar cells during accelerated ageing
No full textThe commercialization of perovskite solar cells (PSCs) depends on breakthroughs in stability, yet the complex degradation mechanisms complicate the study of their long-term performance. This work investigates the role of non-radiative recombination in PSC stability by establishing a quantitative link between defect-related parameters and device performance. We found that defect-induced minor losses in open-circuit voltage (VOC) are accompanied by significant reductions in charge extraction efficiency (short-circuit current and fill factor). Through non-destructive, contactless photoluminescence characterization, we decoupled non-radiative recombination effects in various perovskite stacks before and after accelerated ageing. The quasi-Fermi level splitting (QFLS) losses in devices during the ageing process primarily originate from the perovskite bulk rather than the interfaces, with most of these losses occurring within the first 50 hours of ageing. We find that optimizing perovskite composition and improving crystal quality to suppress defect formation during ageing can extend photo-thermal stability by more than a factor of 50
Mechanical properties of the fuel electrode support for protonic ceramic fuel and electrolysis cells
No full text
Unraveling Degradation Phenomena within Proton Exchange Membrane Electrolytic Cells through Modeling
No full textVisualisation of the oxygen gas coverage in the anodic flow field and its correlation to the performance of a PEM electrolysis cell
No full textEvaluation of Gas Bubble Coverage in a Flow Field by Deep Learning-Based Analysis: The Impact of Gas Content on PEM Electrolyzer Performance
No full textCo-Simulation for Automated Optimization of Integrated Cryogenic Qubit Electronics
No full textOne approach to scaling quantum computers requires large-scale integration of qubit control electronics at cryogenic temperatures close to the qubits to reduce the wiring bottleneck, signal latencies, and improve the modularity of the system. Finding optimized specifications by accurately simulating the qubit-electronics interface allows optimal budgeting of resources (heat dissipation, area) for scalable quantum computers. We propose a systematic and efficient design flow for the optimization of integrated electronic circuits using a co-simulation methodology that covers the entire development process from the concept phase to transistor-level design. As a use case, we choose the shuttling of spin qubits inside quantum dots. The automated workflow optimizes the hardware parameters of the circuit during the design phase of the integrated circuit. Based on the simulated performance of our low-power circuits, we argue that well-designed integrated electronics can replace critically-scaling room-temperature electronics for the given use case
