There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

Fast parallel algorithms for short-range molecular dynamics

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

The energy costs associated with separating tightly bound excitons (photoinduced electron-hole pairs) and extracting free charges from highly disordered low-mobility networks represent fundamental losses for many low-cost photovoltaic technologies. We report a low-cost, solution-processable solar cell, based on a highly crystalline perovskite absorber with intense visible to near-infrared absorptivity, that has a power conversion efficiency of 10.9% in a single-junction device under simulated full sunlight. This "meso-superstructured solar cell" exhibits exceptionally few fundamental energy losses; it can generate open-circuit photovoltages of more than 1.1 volts, despite the relatively narrow absorber band gap of 1.55 electron volts. The functionality arises from the use of mesoporous alumina as an inert scaffold that structures the absorber and forces electrons to reside in and be transported through the perovskite.

https://science.sciencemag.org/content/sci/early/2012/10/03/science.1228604.full.pdf

Efficient Hybrid Solar Cells Based on Meso-Superstructured Organometal Halide Perovskites

Single-Junction Organic Solar Cell with over 15% Efficiency Using Fused-Ring Acceptor with Electron-Deficient Core

We develop and evaluate two methods aimed at enhancing the mechanical resistance and stretchability of bulk heterojunction active layers in organic solar cells while maintaining photovoltaic performance intact. These techniques consist of adding a cross-linker or an elastomer into the active layer. First, we study P3HT:PC 61 BM blend as a reference polymer:fullerene acceptor system for our conceptual demonstration. The diazido cross-linker selectively reacts with PC 61 BM molecules and the resulting blend shows an overall softening eﬀect of the mix, while the power conversion eﬃciency (PCE) increases by up to 20%, which we attribute to increased aggregation of P3HT. Addition of elastomers aﬀects the blend diﬀerently: the crystallinity of the donor decreases, which can have a detrimental eﬀect on the PCE of certain materials. However, the elastomer method is found to be considerably more universal by acting as a mechanical softener in modern fullerene-free blend systems as well. In particular, SEBS elastomer displayed a tailored elasticity with various fullerene and non-fullerene blends: P3HT:PC 61 BM, PCE10:PC 71 BM, and PCE13:IT-4F. The potential of our SEBS process is demonstrated in PCE13:IT-4F:SEBS solar cells with a PCE of 11.5%. This versatile approach highlights the ease of manufacturing and scalability achieved by the solution casting processes, along with the high compatibility of acceptor and donor blends.

Versatile methods for improving the mechanical properties of fullerene and non-fullerene bulk heterojunction layers to enable stretchable organic solar cells † of Materials Chemistry C

CrystalExplorer: An Interactive Knowledge-Assisted System for Visual Design of Solar Cell Crystal Structures

Cover Picture: Look fast: Crystallization of conjugated molecules during solution shearing probed in-situ and in real time by X-ray scattering (Phys. Status Solidi RRL 3/2013)

Embodiments of the present disclosure describe a method of fabricating a semiconducting material, comprising fixing a first substrate to a second substrate via a bonding material sufficient to form a two-substrate support with a cavity region, applying an organo-lead halide perovskite precursor solution to the cavity region of the two-substrate support, and annealing sufficient to form in the cavity region a semiconducting material including an organo-lead halide perovskite thin single crystal. Embodiments of the present disclosure further describe a transistor comprising a source terminal, a drain terminal, a channel layer extending between the source terminal and the drain terminal and including an organo-lead halide perovskite thin single crystal, a gate terminal, and an insulating layer separating the gate terminal from the source terminal, drain terminal, and channel layer sufficient to form a transistor.

Organo-lead halide perovskites thin single crystals

https://onlinelibrary.wiley.com/doi/pdf/10.1002/adma.201770014

Perovskite Photovoltaics: Hybrid Perovskite Thin‐Film Photovoltaics: In Situ Diagnostics and Importance of the Precursor Solvate Phases (Adv. Mater. 2/2017)

Aram Amassian

Papers

Versatile methods for improving the mechanical properties of fullerene and non-fullerene bulk heterojunction layers to enable stretchable organic solar cells † of Materials Chemistry C

CrystalExplorer: An Interactive Knowledge-Assisted System for Visual Design of Solar Cell Crystal Structures

Cover Picture: Look fast: Crystallization of conjugated molecules during solution shearing probed in-situ and in real time by X-ray scattering (Phys. Status Solidi RRL 3/2013)

Organo-lead halide perovskites thin single crystals

Perovskite Photovoltaics: Hybrid Perovskite Thin‐Film Photovoltaics: In Situ Diagnostics and Importance of the Precursor Solvate Phases (Adv. Mater. 2/2017)