?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F20205%2F&rft.title=Charge+Transport+in+Disordered+Materials&rft.creator=Gagorik%2C+Adam&rft.description=This+thesis+is+focused+on+on+using+Monte+Carlo+simulation+to+extract+device+relevant+properties%2C+such+as+the+current+voltage+behavior+of+transistors+and+the+efficiency+of+photovoltaics%2C+from+the+hopping+transport+of+molecules.%0D%0ASpecifically%2C+simulation+is+used+to+study+organic+field-effect+transistors+(OFETs)+and+organic+photovoltaics+(OPVs).%0D%0AFor+OFETs%2C+the+current+was+found+to+decrease+with+increasing+concentration+of+traps+and+barriers+in+the+system.%0D%0AAs+the+barrier%2Ftrap+concentration+approaches+100%25%2C+the+current+recovers+as+carrier+begin+to+travel+through+the+manifold+of+connected+trap+states.%0D%0ACoulomb+interactions+between+like+charges+are+found+to+play+a+role+in+removing+carriers+from+trap+states.%0D%0AThe+equilibrium+current+in+OFETs+was+found+to+be+independent+of+charge+injection+method%2C+however%2C+the+finite+size+of+devices+leads+to+an+oscillatory+current.%0D%0AFourier+transforms+of+the+electrical+current+show+peaks+that+vary+non-linearly+with+device+length%2C+while+being+independent+of+device+width.%0D%0AThis+has+implications+for+the+mobility+of+carriers+in+finite+sized+devices.%0D%0ALastly%2C+the+presence+of+defects+and+high+barriers+(%3E+0.4+eV)+was+found+to+produce+negative+differential+resistance+in+the+saturation+region+of+OFET+curves%2C+unlike+traps.%0D%0AWhile+defects+and+barriers+prohibit+carriers+from+reaching+the+drain+at+high+voltages%2C+the+repulsive+interaction+between+like+charged+carriers+pushes+charges+around+the+defects.%0D%0AFor+OPVs%2C+the+effects+of+device+morphology+and+charge+delocalization+were+studied.%0D%0AFill+factors+increased+with+domain+size+in+monolayer+isotropic+morphologies%2C+but+decreased+for+band+morphologies.%0D%0AIn+single-phase+systems+without+Coulomb+interactions%2C+astonishingly+high+fill+factors+(70%25)+were+found.%0D%0AIn+multilayer+OPVs%2Ca+complex+interplay+of+domain+size%2C+connectivity%2C+tortuosity%2C+interface+trapping%2C+and+delocalization+determined+efficiency.&rft.date=2014-01-30&rft.type=University+of+Pittsburgh+ETD&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F20205%2F1%2FAdamGagorikThesis.pdf&rft.identifier=++Gagorik%2C+Adam++(2014)+Charge+Transport+in+Disordered+Materials.++Doctoral+Dissertation%2C+University+of+Pittsburgh.++++(Unpublished)++