Investigation on Transport Mechanisms and Interfacial Properties of Solar Cells By Simulation

Understanding the charge transport mechanisms and the surface interfacial properties of polymer-based solar cells is the prerequisite to crack the working mechanisms and improve the performances of photovoltaic devices. In order to increase the power conversion efficiency of dye sensitized solar cells and polymer-based hybrid photovoltaic, experimental approaches have been widely used to change the chemical structures, morphologies and recipes of photovoltaic components. The introduction of simulation approaches to experimental researchers provides a new method to analyze the experimental results and guide the research directions for dye sensitized solar cells. As the mainstream materials simulation technique, molecular dynamics simulation, Monte Carlo simulation and quantum mechanical calculations can only investigate some components of organic photovoltaic, rather than device level. Thus suitable models to simulate the mechanisms and characteristics of organic solar cells at the device level are needed. We propose a coarse grain model based on molecular dynamics simulation protocol, to simulate the functions and performances of dye sensitized solar cells at the nanoscale. During the developments of dye sensitized solar cells coarse grain model, programming techniques are adopted to control the reaction procedures in dye sensitized solar cells. In addition, coarse grain force field is developed to describe the reactions between different components of dye sensitized solar cells. The coarse grain model can be used to trace transport mechanisms, calculate the relation between current intensity and voltage, and explore the mobility of electrons. It is the first time to simulate the charge generation and recombination processes and power conversion efficiencies of the dye sensitized solar cells by molecular dynamic simulation protocol at the device level. With this new model, we can analyze the main factors determining the current intensity and the performances of dye sensitized solar cells. The simulation results show that the curve of current-voltage are similar to experimental results and the power conversion efficiencies of coarse grain model are close to real devices. We verify that the DSSCs coarse grain model is a promising method to study and predict the performance of photovoltaic devices. We also employ classical molecular dynamic simulation approaches to explore the surface properties of polymer-based hybrid photovoltaic. The investigations on the interfacial structure of surface-modified cadmium sulfide nanoparticles in contact with several substituted poly(phenylene ethynylene)s can identify the preferred location of functional groups and the impacts of covalent bonds between the polymer and the nanoparticle. The simulation results show that polymers with long alkyl side chains containing hydroxyl groups were the best candidates to approach the trimethoxysilyl shell of the cadmium sulfide nanoparticle surfaces and to form covalent linkages.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Polymer Engineering

Grantor dc:publisher

University of Akron

Year dc:date

2013

Author dc:creator

• Liu, Hua

Contributors dc:contributor

• Heinz, Hendrik

• Polymers
• Polymer Solar Cells

Statement dc:rights

• unrestricted
• This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

Language dc:language

English

Repository record dc:identifier

http://rave.ohiolink.edu/etdc/view?acc_num=akron1365873270

OAI identifier oai:identifier

oai:etd.ohiolink.edu:akron1365873270