Boundary-reaction-diffusion model for oscillatory zoning in binary crystals grown from solution

A minimally-resolved immersed boundary model for reaction-diffusion problems.

We develop an immersed boundary approach to modeling reaction-diffusion processes in dispersions of reactive spherical particles, from the diffusion-limited to the reaction-limited setting. We represent each reactive particle with a minimally-resolved "blob" using many fewer degrees of freedom per particle than standard discretization approaches. More complicated or more highly resolved particl...

A Metastable Spike Solution for a Nonlocal Reaction-Diffusion Model

An asymptotic reduction of the Gierer Meinhardt activator-inhibitor system in the limit of large inhibitor diiusivity leads to a singularly perturbed non-local reaction diiusion equation for the activator concentration. In the limit of small activator diiusivity, a one-spike solution to this non-local model is constructed. The spectrum of the eigenvalue problem associated with the linearization...

Solar cells. Electron-hole diffusion lengths > 175 μm in solution-grown CH3NH3PbI3 single crystals.

Long, balanced electron and hole diffusion lengths greater than 100 nanometers in the polycrystalline organolead trihalide compound CH3NH3PbI3 are critical for highly efficient perovskite solar cells. We found that the diffusion lengths in CH3NH3PbI3 single crystals grown by a solution-growth method can exceed 175 micrometers under 1 sun (100 mW cm(-2)) illumination and exceed 3 millimeters und...

Electron-hole diffusion lengths >175 μm in solution-grown CH3NH3PbI3 single crystals

Periodic Travelling Wave Selection by Dirichlet Boundary Conditions in Oscillatory Reaction-Diffusion Systems

Periodic travelling waves are a fundamental solution form in oscillatory reactiondiffusion equations. Here I discuss the generation of periodic travelling waves in a reaction-diffusion system of the generic λ-ω form. I present numerical results suggesting that when this system is solved on a semi-infinite domain subject to Dirichlet boundary conditions in which the variables are fixed at zero, ...