To understand the full potential of organic semiconductors we need to be able to control their crystallinity, a process not well understood. Here we investigate three organic semiconductors, rubrene, 2,2′,2-(1,3,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi) and N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB), that we have shown to crystallize at large scale. In this report we show crystalline domains millimeters in scale and successful homoepitaxy. Being able to tune the thickness of the crystalline layer is an important process for implementing these films into devices. Previously unknown, the crystal structure of TPBi is determined from a single crystal grown via sublimation. The crystallized films display a reduced Stokes shift compared to the amorphous films potentially leading to a factor of three and factor of two increase in exciton diffusion length for NPB and TPBi, respectively. Previous work done on crystalline rubrene/C60 heterojunctions has shown extreme delocalization of the charge transfer state at the interface resulting in reduced voltage loss in solar cells made with this heterojunction. Continuing this work we investigate the charge transfer state of crystalline NPB/C60 and crystalline rubrene/Cl-Cl<sub>6,12</sub>BsubPc solar cell systems.

Crystal growth of organic semiconductors and the effects of crystalline heterojunctions on charge transfer states

Macromolecular Chemistry: The Second Century

[Author Benefits](https://scimeetings.acs.org/?utm_source=pubs_content_marketing&utm_medium=website&utm_campaign=0320_MCF_NPI_Launch_Spring_Homepage&ref=pubs_content_marketing)

[How to use SciMeetings](https://storage.googleapis.com/dl.morressier.com/acs/SciMeetings-ACSSpring2020-HowToGuide_M3020-Final.pdf)

[Frequently Asked Questions](https://storage.googleapis.com/dl.morressier.com/acs/SciMtng_ACSNMSp2020_FAQ_M3120_Final.pdf)

ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.