Codice  QDD 53 
Titolo  Analytical and Numerical Study of Photocurrent Transients in Nanoscale Organic Solar Cells 
Data  20090930 
Autore/i  de Falco, C.; Sacco, R.; Verri, M. 
Link  Download full text  Pubblicato  Computer Methods in Applied Mechanics and Engineering 
Abstract  In this article, we deal with the mathematical
modeling and numerical simulation of photocurrent transients in nanoscale monolayer Organic polymer Solar Cells (OSCs). The mathematical model consists of a system of nonlinear diffusionreaction partial differential equations (PDEs) with electrostatic convection, coupled to a kinetic ordinary differential equation (ODE).
We propose a suitable reformulation of the model
which makes it similar to the classical driftdiffusion system for inorganic semiconductor devices. This allows us, on the one hand, to prove the existence of a solution for the problem
in both stationary and transient conditions
and, on the other hand, to better highlight
the role of exciton dynamics in determining the device turnon time. For the numerical treatment of the problem, we carry out a temporal semidiscretization using an implicit adaptive method, and the resulting sequence of differential subproblems is linearized using the NewtonRaphson method with inexact evaluation of the Jacobian. Then, we use exponentially fitted finite elements for the spatial discretization, and we carry out a thorough validation of the computational model by extensively investigating
the impact of the model parameters on photocurrent transient times.
A modified version of this paper will appear in Comp. Meth. Appl. Mech. Engrg. (2010)

