All About the Interface: Do Residual Contaminants at A High‐Quality h‐BN Monolayer Perylene Diimide Interface Cause Charge Trapping?
Abstract Intrinsic charge transport in molecularly thin organic semiconducting crystals is critically sensitive to the quality of the interfaces required to perform the electrical measurements. Most prominent are the dielectric–semiconductor and semiconductor–metal interface. While impacts from the...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley-VCH
2022-04-01
|
| Series: | Advanced Materials Interfaces |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/admi.202101701 |
| _version_ | 1797690177917812736 |
|---|---|
| author | Lukas Renn Lisa S. Walter Kenji Watanabe Takashi Taniguchi R. Thomas Weitz |
| author_facet | Lukas Renn Lisa S. Walter Kenji Watanabe Takashi Taniguchi R. Thomas Weitz |
| author_sort | Lukas Renn |
| collection | DOAJ |
| description | Abstract Intrinsic charge transport in molecularly thin organic semiconducting crystals is critically sensitive to the quality of the interfaces required to perform the electrical measurements. Most prominent are the dielectric–semiconductor and semiconductor–metal interface. While impacts from the latter on charge transport can be extracted by four‐terminal measurements, the impact of the dielectric interface can only be minimized, typically by utilizing inert dielectrics. Here, it is shown that charge transport in organic field‐effect transistors based on the n‐type small molecule N, N′‐di((S)‐1‐methylpentyl)‐1,7(6)‐dicyano‐perylene‐3,4:9,10‐bis(dicarboximide) (PDI1MPCN2) can be improved up to one order of magnitude by using hexagonal boron nitride (h‐BN) as dielectric, compared to a standard SiO2 substrate. Using temperature‐dependent electrical measurements, the charge‐transport properties of devices are systematically analyzed, and high four‐terminal mobilities of up to 5.0 cm2 V−1 s−1 are obtained. The high mobility likely stems from decreased charge‐carrier trapping at the semiconductor‐dielectric interface due to the smooth surface of the inert h‐BN. Nevertheless, the temperature dependencies of the mobility, threshold voltage, and interface‐state trap density suggest that charge‐carrier trapping at the dielectric‐semiconductor interface still exists. By comparing the data to transport studies performed on thin air‐gapped organic films, it is concluded that an interfacial layer (likely water or solvent residues) between h‐BN and the monolayer PDI1MPCN2 causes charge trapping. |
| first_indexed | 2024-03-12T01:56:48Z |
| format | Article |
| id | doaj.art-0b24e4a7b6b64acd8c8dc386fda141ea |
| institution | Directory Open Access Journal |
| issn | 2196-7350 |
| language | English |
| last_indexed | 2024-03-12T01:56:48Z |
| publishDate | 2022-04-01 |
| publisher | Wiley-VCH |
| record_format | Article |
| series | Advanced Materials Interfaces |
| spelling | doaj.art-0b24e4a7b6b64acd8c8dc386fda141ea2023-09-08T03:32:46ZengWiley-VCHAdvanced Materials Interfaces2196-73502022-04-01910n/an/a10.1002/admi.202101701All About the Interface: Do Residual Contaminants at A High‐Quality h‐BN Monolayer Perylene Diimide Interface Cause Charge Trapping?Lukas Renn0Lisa S. Walter1Kenji Watanabe2Takashi Taniguchi3R. Thomas Weitz41st Institute of Physics Faculty of Physics Georg‐August‐University Göttingen Germany1st Institute of Physics Faculty of Physics Georg‐August‐University Göttingen GermanyResearch Center for Functional Materials National Institute for Materials Science 1‐1 Namiki Tsukuba 305‐0044 JapanInternational Center for Materials Nanoarchitectonics National Institute for Materials Science 1‐1 Namiki Tsukuba 305‐0044 Japan1st Institute of Physics Faculty of Physics Georg‐August‐University Göttingen GermanyAbstract Intrinsic charge transport in molecularly thin organic semiconducting crystals is critically sensitive to the quality of the interfaces required to perform the electrical measurements. Most prominent are the dielectric–semiconductor and semiconductor–metal interface. While impacts from the latter on charge transport can be extracted by four‐terminal measurements, the impact of the dielectric interface can only be minimized, typically by utilizing inert dielectrics. Here, it is shown that charge transport in organic field‐effect transistors based on the n‐type small molecule N, N′‐di((S)‐1‐methylpentyl)‐1,7(6)‐dicyano‐perylene‐3,4:9,10‐bis(dicarboximide) (PDI1MPCN2) can be improved up to one order of magnitude by using hexagonal boron nitride (h‐BN) as dielectric, compared to a standard SiO2 substrate. Using temperature‐dependent electrical measurements, the charge‐transport properties of devices are systematically analyzed, and high four‐terminal mobilities of up to 5.0 cm2 V−1 s−1 are obtained. The high mobility likely stems from decreased charge‐carrier trapping at the semiconductor‐dielectric interface due to the smooth surface of the inert h‐BN. Nevertheless, the temperature dependencies of the mobility, threshold voltage, and interface‐state trap density suggest that charge‐carrier trapping at the dielectric‐semiconductor interface still exists. By comparing the data to transport studies performed on thin air‐gapped organic films, it is concluded that an interfacial layer (likely water or solvent residues) between h‐BN and the monolayer PDI1MPCN2 causes charge trapping.https://doi.org/10.1002/admi.202101701charge transportfield‐effect transistorinterfaceorganic semiconductorvan‐der‐Waals |
| spellingShingle | Lukas Renn Lisa S. Walter Kenji Watanabe Takashi Taniguchi R. Thomas Weitz All About the Interface: Do Residual Contaminants at A High‐Quality h‐BN Monolayer Perylene Diimide Interface Cause Charge Trapping? Advanced Materials Interfaces charge transport field‐effect transistor interface organic semiconductor van‐der‐Waals |
| title | All About the Interface: Do Residual Contaminants at A High‐Quality h‐BN Monolayer Perylene Diimide Interface Cause Charge Trapping? |
| title_full | All About the Interface: Do Residual Contaminants at A High‐Quality h‐BN Monolayer Perylene Diimide Interface Cause Charge Trapping? |
| title_fullStr | All About the Interface: Do Residual Contaminants at A High‐Quality h‐BN Monolayer Perylene Diimide Interface Cause Charge Trapping? |
| title_full_unstemmed | All About the Interface: Do Residual Contaminants at A High‐Quality h‐BN Monolayer Perylene Diimide Interface Cause Charge Trapping? |
| title_short | All About the Interface: Do Residual Contaminants at A High‐Quality h‐BN Monolayer Perylene Diimide Interface Cause Charge Trapping? |
| title_sort | all about the interface do residual contaminants at a high quality h bn monolayer perylene diimide interface cause charge trapping |
| topic | charge transport field‐effect transistor interface organic semiconductor van‐der‐Waals |
| url | https://doi.org/10.1002/admi.202101701 |
| work_keys_str_mv | AT lukasrenn allabouttheinterfacedoresidualcontaminantsatahighqualityhbnmonolayerperylenediimideinterfacecausechargetrapping AT lisaswalter allabouttheinterfacedoresidualcontaminantsatahighqualityhbnmonolayerperylenediimideinterfacecausechargetrapping AT kenjiwatanabe allabouttheinterfacedoresidualcontaminantsatahighqualityhbnmonolayerperylenediimideinterfacecausechargetrapping AT takashitaniguchi allabouttheinterfacedoresidualcontaminantsatahighqualityhbnmonolayerperylenediimideinterfacecausechargetrapping AT rthomasweitz allabouttheinterfacedoresidualcontaminantsatahighqualityhbnmonolayerperylenediimideinterfacecausechargetrapping |