The Structural Origin of Electron Injection Enhancements with Fulleropyrrolidine Interlayers

Published

February 25, 2016

Author(s)

Lee J. Richter, Hyunbok Lee, Christopher McNeil, Eliot Gann, Lars Thomsen, S. Park, J. Jeong, Z. A. Page, Egle Puodziukynaite, Todd Emrick, Alejandro Briseno, John C. Stephenson, Dean M. DeLongchamp

Abstract

Market demand for ubiquitous, increased functionality products at low cost (the internet of things) is spurring development in additive, solution processing of electronic devices. Performance in thin-film functional devices, be they transistors, diodes, or receivers (both solar cells and detectors), critically depends on efficient charge injection and extraction at contacts. For traditional, high temperature processed semiconductors, this is achieved by creating ohmic contacts via doping. For most solution processed materials, both organic and inorganic, doping is not viable and charge injection must be controlled primarily by band alignment between the contact and active layer; the hole/electron injection barrier is determined by the energetic difference between the Fermi level of an electrode and the transport level of the semiconductor . This has led to considerable research in solution processable work function modifiers (WFMs) for use as both hole injection layers (HILs)[ref] and electron injection layers (EILs).In this paper, we present detailed electronic structure studies of fulleropyrrolidines on ITO and detailed orientation and alignment studies of the amine and sulfobetaine groups with NEXAFS and vibrationally resonant sum-frequency generation (VRSFG). We establish that the common mode of action of the materials on both metals and oxides is linked to the interfacial organization of the polar/charged functional groups.

Citation

Advanced Materials Interfaces

Volume

3

Pub Type

Journals

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DOI Link

Keywords

NEXAFS, Sum Frequency Generation, Organic Electronics, Contacts, Carrier injection, work function

Citation

Richter, L. , Lee, H. , McNeil, C. , Gann, E. , Thomsen, L. , Park, S. , Jeong, J. , Page, Z. , Puodziukynaite, E. , Emrick, T. , Briseno, A. , Stephenson, J. and DeLongchamp, D. (2016), The Structural Origin of Electron Injection Enhancements with Fulleropyrrolidine Interlayers, Advanced Materials Interfaces, [online], https://doi.org/10.1002/admi.201500852 (Accessed October 14, 2024)