TY - JOUR
T1 - ITO Work Function Tunability by Polarizable Chromophore Monolayers
AU - Gankin, Alina
AU - Mervinetsky, Evgeniy
AU - Alshanski, Israel
AU - Buchwald, Jörg
AU - Dianat, Arezoo
AU - Gutierrez, Rafael
AU - Cuniberti, Gianaurelio
AU - Sfez, Ruthy
AU - Yitzchaik, Shlomo
N1 - Funding Information: The authors would like to thank the RECORD-IT project. This project received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement no. 664786. S.Y. is the Binjamin H. Birstein Chair in Chemistry. TU Dresden gratefully acknowledges computing time by the Center for Information Services and High Performance Computing (ZIH). R.S. is grateful for the support by Azrieli College of EngineeringJerusalem Research Fund. The authors would like to thank Dr. Vitaly Gutkin for XPS analysis. Publisher Copyright: © 2019 American Chemical Society.
PY - 2019/2/26
Y1 - 2019/2/26
N2 - The ability to tune the electronic properties of oxide-bearing semiconductors such as Si/SiO 2 or transparent metal oxides such as indium-tin oxide (ITO) is of great importance in both electronic and optoelectronic device applications. In this work, we describe a process that was conducted on n-type Si/SiO 2 and ITO to induce changes in the substrate work function (WF). The substrates were modified by a two-step synthesis comprising a covalent attachment of coupling agents' monolayer followed by in situ anchoring reactions of polarizable chromophores. The coupling agents and chromophores were chosen with opposite dipole orientations, which enabled the tunability of the substrates' WF. In the first step, two coupling agents with opposite molecular dipole were assembled. The coupling agent with a negative dipole induced a decrease in WF of modified substrates, while the coupling agent with a positive dipole produced an increase in WFs of both ITO and Si substrates. The second modification step consisted of in situ anchoring reaction of polarizable chromophores with opposite dipoles to the coupling layer. This modification led to an additional change in the WFs of both Si/SiO 2 and ITO substrates. The WF was measured by contact potential difference and modeled by density functional theory-based theoretical calculations of the WF for each of the assembly steps. A good fit was obtained between the calculated and experimental trends. This ability to design and tune the WF of ITO substrates was implemented in an organic electronic device with improved I-V characteristics in comparison to a bare ITO-based device.
AB - The ability to tune the electronic properties of oxide-bearing semiconductors such as Si/SiO 2 or transparent metal oxides such as indium-tin oxide (ITO) is of great importance in both electronic and optoelectronic device applications. In this work, we describe a process that was conducted on n-type Si/SiO 2 and ITO to induce changes in the substrate work function (WF). The substrates were modified by a two-step synthesis comprising a covalent attachment of coupling agents' monolayer followed by in situ anchoring reactions of polarizable chromophores. The coupling agents and chromophores were chosen with opposite dipole orientations, which enabled the tunability of the substrates' WF. In the first step, two coupling agents with opposite molecular dipole were assembled. The coupling agent with a negative dipole induced a decrease in WF of modified substrates, while the coupling agent with a positive dipole produced an increase in WFs of both ITO and Si substrates. The second modification step consisted of in situ anchoring reaction of polarizable chromophores with opposite dipoles to the coupling layer. This modification led to an additional change in the WFs of both Si/SiO 2 and ITO substrates. The WF was measured by contact potential difference and modeled by density functional theory-based theoretical calculations of the WF for each of the assembly steps. A good fit was obtained between the calculated and experimental trends. This ability to design and tune the WF of ITO substrates was implemented in an organic electronic device with improved I-V characteristics in comparison to a bare ITO-based device.
UR - http://www.scopus.com/inward/record.url?scp=85061934171&partnerID=8YFLogxK
U2 - https://doi.org/10.1021/acs.langmuir.8b03943
DO - https://doi.org/10.1021/acs.langmuir.8b03943
M3 - Article
C2 - 30707589
SN - 0743-7463
VL - 35
SP - 2997
EP - 3004
JO - Langmuir
JF - Langmuir
IS - 8
ER -