Graphene as interface modifier in ITO and ITO-Cr electrodes
| Autor: | Joyce R. Araujo, Rodrigo B. Capaz, Leticia A. Silva, Alexander M. Silva, Rafael V. Curti, Sanair M. Oliveira, Jéssica M.M. Luzardo, Rogerio Valaski |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Materials science Graphene Organic devices Thin layer Oxide General Physics and Astronomy 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences law.invention chemistry.chemical_compound Chemical engineering chemistry law 0103 physical sciences Electrode Chromium oxide General Materials Science Work function 0210 nano-technology Deposition (law) |
| Zdroj: | Current Applied Physics. 20:846-852 |
| ISSN: | 1567-1739 |
| DOI: | 10.1016/j.cap.2020.04.004 |
| Popis: | We explore graphene as interface modifier for electrodes in optoelectronic organic devices by measuring the electrical properties of ITO/graphene and ITO/Cr/graphene. For this purpose, exfoliated graphene (EG) was electrochemically synthesized and deposited by spray-pyrolysis. The built-in voltage (Vbi) values were 450 mV for the ITO/CuPc/Al reference, 750 mV for ITO/Cr/graphene/CuPc/Al and 1000 mV for ITO/graphene/CuPc/Al device structures. From these results, we estimate the work functions as 3.20 eV, 3.45 eV and 4.75 eV for ITO/EG, ITO/Cr/EG and ITO. To understand how the work function changes, we carried out first-principles calculations based on density-functional theory (DFT) where Cr work function (~4.2 eV) is not modified by the deposition of pristine graphene; however there is a substantial increase (from 4.2 eV to 5.2 eV), upon deposition of graphene oxide (GO), resulting from a complete transfer of O atoms from the GO sheet to the Cr surface forming a thin layer of chromium oxide. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect