kMC for OPV Simulations in the Python Environment
The kinetic Monte Carlo (kMC) algorithm with first reaction method (FRM) can be appiled for the charge transport simulation of the organic photovoltaic cells.
kMC can be used for all three parts which are modelings for morphology generation, exciton dissociation and charge injection/extraction.
1. Morpology Modeling
For morphology modeling, the Ising Hamiltonian method can be used. First, random morphology is generated by applying random position p and n materials. If the size of sites is L * L * L, around halft sites ~ L * L * L /2 are set to p materials such as +1 for each element of the L * L * L morphology matrix while the other half sites are set to n materials such as -1, Note that the total number of p-material and n-materials sites must be equal to the total number of sites, which is L * L * L. That is, any site is belonging to either p or n-material.
2. Exciton Dissociation Modeling
Exciton dissociation can also be modeled by kMC algorithm with the first reaction method (FRM). The exciton is generated with a rate of 500ps/cm2 by incidence of a photon. Each arrived photon can generate an exciton which has a lifetime of 500ps^-1. Therefore, the average drift length of an exciton becomes approximately 10nm. The physical constants for exciton generation, lifetime are fixed.
3. Charge Injection and Extraction Modeling
kMC can be used for all three parts which are modelings for morphology generation, exciton dissociation and charge injection/extraction.
1. Morpology Modeling
For morphology modeling, the Ising Hamiltonian method can be used. First, random morphology is generated by applying random position p and n materials. If the size of sites is L * L * L, around halft sites ~ L * L * L /2 are set to p materials such as +1 for each element of the L * L * L morphology matrix while the other half sites are set to n materials such as -1, Note that the total number of p-material and n-materials sites must be equal to the total number of sites, which is L * L * L. That is, any site is belonging to either p or n-material.
2. Exciton Dissociation Modeling
Exciton dissociation can also be modeled by kMC algorithm with the first reaction method (FRM). The exciton is generated with a rate of 500ps/cm2 by incidence of a photon. Each arrived photon can generate an exciton which has a lifetime of 500ps^-1. Therefore, the average drift length of an exciton becomes approximately 10nm. The physical constants for exciton generation, lifetime are fixed.
3. Charge Injection and Extraction Modeling
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