synthesis and characterization of block copolymers for organic … · 2016. 8. 3. · 00 2015 ppg...

00 2015 PPG Undergraduate Research Fellowship Program H H Synthesis and Characterization of Block Copolymers for Organic Photovoltaics Bryan Smith 1 , Melissa Aplan 1 , Dr. Youngmin Lee 1,2 , and Dr. Enrique Gomez 1,2 1 Department of Chemical Engineering, Pennsylvania State University; 2 Material Science Institute, Pennsylvania State University The PPG Undergraduate Research Fellowship Program is supported by the PPG Research Foundation through the Materials Research Institute Introduction Target Copolymers Donor End Group Control Reactions Results & Characterization Working towards… • Higher efficiency • Greater understanding • New materials • Cheaper production • Flexibility Why block copolymer? • Higher performance all polymer active layer • Morphology control • Better donor/acceptor interface • Block crystallization P3HT-b-PCPDTBT PCPDT-b-PNDIBT P3HT-b-PNDIT P3HT-b-PFBT Factors we consider… • Literature homopolymer blend performance • HOMO/LUMO levels • Band gap • Range of absorption Donor Acceptor Suzuki Coupling Kumada Coupling P3HT-b-PFTBT solar cells with record near 3% efficiency dramatically outperform P3HT-PFTBT blend cells MALDI-TOF End Group Analysis • Intensities correspond to end group distribution • Control critical for synthesis pathway • Affected by O 2 ,H 2 O, temperature, Grignard quantity P3HT-b-PFBT Synthesis Scheme NMR Analysis • Calculate mole and mass fraction from peak integration • Limited by solubility • Paired with GPC, UV-Vis to confirm block copolymerization Summary • Refined end group functionalized P3HT synthesis • Synthesized P3HT-b-PFBT Future Work • Synthesize other targets • Test devices with new active layers • Improve accuracy and range of characterization Suzuki Kumada Example P3HT-b-PFTBT GPC Analysis • Indicates purity • Comparison to homopolymer P3HT data C. Guo, et al., Nano Lett., 2013, 13, 2957 UV-Vis Analysis • Block copolymer spectra closely resembles sum of homopolymer spectra • Spectra of same thickness films can be analyzed to report volume fraction upon creation of homopolymer standards H H a b c b a c c 11 12 13 14 15 16 17 18 19 Time (mins) P3HT Homopolymer P3HT-b-PFTBT H Br

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2015PPGUndergraduateResearchFellowshipProgram

Synthesis and Characterization of Block Copolymers for Organic PhotovoltaicsBryan Smith1, Melissa Aplan1, Dr. Youngmin Lee1,2, and Dr. Enrique Gomez1,2

1Department of Chemical Engineering, Pennsylvania State University; 2Material Science Institute, Pennsylvania State University

The PPG Undergraduate Research Fellowship Program is supported by the PPG Research Foundation through the Materials Research Institute

Introduction Target Copolymers

Donor End Group ControlReactions

Results & CharacterizationWorkingtowards…• Higherefficiency• Greaterunderstanding• Newmaterials• Cheaperproduction• Flexibility

Whyblockcopolymer?• Higherperformanceall

polymeractivelayer• Morphologycontrol• Betterdonor/acceptor

interface• Blockcrystallization

P3HT-b-PCPDTBT

PCPDT-b-PNDIBT

P3HT-b-PNDIT

P3HT-b-PFBT

Factorsweconsider…• Literaturehomopolymerblendperformance• HOMO/LUMOlevels• Bandgap• Rangeofabsorption

Donor Acceptor

SuzukiCoupling

KumadaCoupling

P3HT-b-PFTBTsolarcellswithrecordnear3%efficiencydramaticallyoutperformP3HT-PFTBTblendcells

MALDI-TOFEndGroupAnalysis• Intensitiescorrespondtoendgroupdistribution• Controlcriticalforsynthesispathway• AffectedbyO2,H2O,temperature,Grignardquantity

P3HT-b-PFBTSynthesisScheme

NMRAnalysis• Calculatemoleandmassfractionfrompeakintegration• Limitedbysolubility• PairedwithGPC,UV-Vistoconfirmblockcopolymerization

Summary• RefinedendgroupfunctionalizedP3HT

synthesis

• SynthesizedP3HT-b-PFBT

Future Work• Synthesizeothertargets• Testdeviceswithnewactivelayers• Improveaccuracyandrangeofcharacterization

Suzuki

Kumada

ExampleP3HT-b-PFTBTGPCAnalysis• Indicatespurity• ComparisontohomopolymerP3HTdata

C.Guo,etal.,NanoLett.,2013,13,2957

UV-VisAnalysis• Blockcopolymerspectracloselyresemblessumofhomopolymer

spectra• Spectraofsamethicknessfilmscanbeanalyzedtoreportvolume