A5001603783- Perovskite Materials and Applications
- Organic Electronics and Photovoltaics
- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- solar cell performance optimization
- Nanowire Synthesis and Applications
- Solid-state spectroscopy and crystallography
- Optical properties and cooling technologies in crystalline materials
- Organic Light-Emitting Diodes Research
- Molecular Junctions and Nanostructures
- Photoreceptor and optogenetics research
- Natural Language Processing Techniques
- Spectroscopy and Quantum Chemical Studies
- Digital Rights Management and Security
- Software Engineering Research
- Advanced Malware Detection Techniques
- Software Testing and Debugging Techniques
- Conducting polymers and applications
- Silicon Nanostructures and Photoluminescence
- Mathematics, Computing, and Information Processing
Google (United States)
2024
University of Cambridge
2013-2017
Cavendish Hospital
2014
Metal halide perovskite crystal structures have emerged as a class of optoelectronic materials, which combine the ease solution processability with excellent optical absorption and emission qualities. Restricting physical dimensions crystallites to few nanometers can also unlock spatial confinement effects, allow large spectral tunability high luminescence quantum yields at low excitation densities. However, most promising rely on lead cationic species, thereby hindering commercial...
Low-bandgap CH3 NH3 (Pbx Sn1-x )I3 (0 ≤ x 1) hybrid perovskites (e.g., ≈1.5-1.1 eV) demonstrating high surface coverage and superior optoelectronic properties are fabricated. State-of-the-art photovoltaic (PV) performance is reported with power conversion efficiencies approaching 10% in planar heterojunction architecture small (<450 meV) energy loss compared to the bandgap (>100 cm2 V-1 s-1 ) intrinsic carrier mobilities.
We demonstrate the successful incorporation of a solution-processable singlet fission material, 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene), into photovoltaic devices. TIPS-pentacene rapidly converts high-energy excitons pairs triplet via fission, potentially doubling photocurrent from photons. Low-energy photons are captured by small-bandgap electron-accepting lead chalcogenide nanocrystals. This is first system that performs with substantial efficiency maximum power...
Multiple exciton generation (MEG) in semiconducting quantum dots is a process that produces multiple charge-carrier pairs from single excitation. MEG possible route to bypass the Shockley-Queisser limit single-junction solar cells but it remains challenging harvest generated by working photovoltaic devices. Initial yields of additional carrier may be reduced due ultrafast intraband relaxation processes compete with at early times. Quantum materials display cooling rates (e.g., PbTe) are...
After 60 years of research, silicon solar cell efficiency saturated close to the theoretical limit, and radically new approaches are needed further improve efficiency. The use tandem systems raises this power conversion limit from 34% 45%. We present advantageous spectral stability using voltage-matched cells with respect their traditional series-connected counterparts experimentally demonstrate how singlet fission can be used produce simple tandems. Our silicon-pentacene shows efficient...
Singlet fission sensitized photovoltaics have the potential to surpass Shockley-Queisser limit for a single-junction structure. We investigate dynamics of triplet excitons resulting from singlet in pentacene and their ionization at C60 heterojunction. model generation diffusion predict spectral response. find length polycrystalline be 40 nm. Poly(3-hexylthiophene) between electrode works both confine also transfer photogenerated into with 30% efficiency. The lower bound quantum efficiency is...
Cesium lead halide nanocrystals, CsPbX3 (X = Cl, Br, I), exhibit photoluminescence quantum efficiencies approaching 100% without the core–shell structures usually used in conventional semiconductor nanocrystals. These high make these crystals ideal candidates for light-emitting diodes (LEDs). However, because of large surface area to volume ratio, halogen exchange between perovskite nanocrystals different compositions occurs rapidly, which is one limiting factors white-light applications...
Carrier multiplication using singlet exciton fission (SF) to generate a pair of spin-triplet excitons from single optical excitation has been highlighted as promising approach boost the photocurrent in photovoltaics (PVs) thereby allowing PV operation beyond Shockley-Queisser limit. The applicability many efficient materials, however, is limited due their poor solubility. For instance, while acene-based organics such pentacene (Pc) show high SF yields (up to200%), plain acene backbone...
Code reviews are a critical part of the software development process, taking significant amount code authors' and reviewers' time. As this reviewer inspects proposed asks author for changes through comments written in natural language. At Google, we see millions per year, authors require an average ~60 minutes active shepherding time between sending review finally submitting change. In our measurements, required work that must devote to address grows almost linearly with number comments....
We propose using natural language outlines as a novel modality and interaction surface for providing AI assistance to developers throughout the software development process. An NL outline code function comprises multiple statements written in concise prose, which partition summarize its main ideas style of literate programming. Crucially, we find that modern LLMs can generate accurate high-quality practice. Moreover, enable bidirectional sync between NL, allowing changes one be automatically...
In photovoltaics (PVs) and artificial photosynthetic systems based on excitons, the question of how energy must be lost in overcoming Coulomb barrier, converting excitons to free charges, is fundamental, as it determines achievable open-circuit voltage or over-potential1-3. Here, using transient steady-state optical spectroscopy we study a model system, pentacene/C60, where pentacene triplet are dissociated form charge transfer states, which show degenerate with excitons. We directly track...
Current matching limits the commercialization of tandem solar cells due to their instability over spectral changes, leading need using concentrators and trackers keep spectrum stable. We demonstrate that voltage-matched systems show far higher performance changes; caused by clouds, dust other variations in atmospheric conditions. Singlet fission is a process organic semiconductors which has shown very efficient, 200%, down-conversion yield generated excitations are long-lived, ideal for...