J-V characteristic of solar cell

This program describes the Current density J and voltage V of solar cell under steady state condition of irradiation using diffusion differential equation [1]. The function J=f(V) is based on short-circuit current density Jsc and calculated for different values of electrode thickness. The program is implemented using the following variables.
Phi : radiation intensity in cm^2/s^-1.
n0 : Electron concentration in cm^-3.
a : Light absorption coefficient in cm^-1.
D : Electron diffusion coefficient in cm^2/s^-1.
q : Charge of electron in c.
Tau : Lifetime of conduction band in s.
L : Electron diffusion length in m.
T : Temparature in k.
k : Boltzmann constant in m^2 Kg s^-2 k^-1.
d : Thickness of thin film in m.
m : Ideality factor derived from experiments.
V : Photovoltage in v.
J : Current density in A/cm^2.
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[1] Sodergren, S., A. Hagfeldt, J. Olsson and S. E. Lindquist, ‘‘Theoretical Models for the Action Spectrum and the CurrentVoltage Characteristics of Microporous Semiconductor-Films in Photoelectrochemical Cells,’’ J. Phys. Chem. 98, 5552–5556, (1994).