Interfacial electronic structures at Fe/pentacene/Fe interfaces

2011 ◽  
Vol 1 (SRMS-7) ◽  
Author(s):  
Yu-Zhan Wang ◽  
Xing-Yu Gao ◽  
Andrew Wee ◽  
Dong-Chen Qi ◽  
Shi Chen
Keyword(s):  
Thin Film ◽  
Binding Energy ◽  
Chemical Reaction ◽  
Electronic Structures ◽  
Hole Injection ◽  
Photoemission Spectroscopy ◽  
Core Hole ◽  
Band Bending ◽  
Screening Effect ◽  
Injection Barrier

We investigate the interfacial electronic structures of the heterojunction Fe/pentacene/Fe on Cu(100) substrate, using synchrotron-based photoemission spectroscopy. No chemical reaction is observed at either Fe/pentacene or pentacene/Fe interface. The hole injection barrier was estimated to be about 0.95 eV between pentacene and under the Fe thin film. C K-edge NEXAFS revealed that the long axis of pentacene molecule was almost perpendicular to the surface plane. With increasing Fe thickness deposited on pentacene film, the pentacene's HOMO shifts to higher binding energy whereas the C 1s binding energy showed an interesting unusual behaviour due to the initial band bending gradually suppressed by the increasing core-hole screening effect.

scholarly journals Electro-Optical Performance of Organic Thin-Film Using HAT(CN)6 between Anode and Organic Materials

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 648 ◽  
Author(s):  
Hong-Gyu Park ◽  
Sang-Geon Park
Keyword(s):  
Thin Film ◽  
Optical Properties ◽  
Current Density ◽  
Carrier Transport ◽  
Hole Injection ◽  
Driving Voltage ◽  
Organic Thin Film ◽  
20 Nm ◽  
Injection Barrier ◽  
A Current

We report the electro-optical properties of an organic thin-film by varying the thickness of 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile (HAT(CN)6), included therein as an interlayer. Devices with HAT(CN)6, which are 7 nm thin films used as interlayers, exhibited good current density–voltage characteristics due to an improved hole injection barrier resulting from carrier ladder effects and carrier transport phenomena. The device without an interlayer showed the worst driving voltage characteristics due to the hole injection barrier. At low driving voltages, a device using 7 nm HAT(CN)6 as an interlayer exhibited a current density about 9.9 times higher than that of a device using 20 nm HAT(CN)6, and showed a current density about 9600 times higher than that of a device without an interlayer. Due to the proper carrier balance, the device using 7 nm HAT(CN)6 as an interlayer achieved a maximum current efficiency of 10.8 cd/A, which was the highest among the devices studied. This shows that the electro-optical properties of devices using HAT(CN)6 as an interlayer are dominated by the holes.

Electronic structures in unoccupied states of Bi thin film studied with two-photon photoemission spectroscopy

2013 ◽  
Vol 267 ◽  
pp. 66-69
Author(s):  
Masaki Imamura ◽  
Shuji Fujimasa ◽  
Kazutoshi Takahashi ◽  
Isamu Yamamoto ◽  
Junpei Azuma ◽  
...  
Keyword(s):  
Thin Film ◽  
Electronic Structures ◽  
Photoemission Spectroscopy ◽  
Two Photon

TEMPERATURE EVOLUTION OF THE PHOTOEMISSION SPECTRA FOR THE Si(111) SURFACE USING THE LASER ANNEALING METHOD

2002 ◽  
Vol 09 (02) ◽  
pp. 769-774
Author(s):  
YUICHI HARUYAMA ◽  
SHINJI MATSUI ◽  
TAICHI OKUDA ◽  
AYUMI HARASAWA ◽  
TOYOHIKO KINOSHITA ◽  
...  
Keyword(s):  
Structural Change ◽  
Transition Temperature ◽  
Binding Energy ◽  
Electronic Structures ◽  
Laser Annealing ◽  
Core Level ◽  
Photoemission Spectroscopy ◽  
Spectral Change ◽  
Surface Band ◽  
Annealing Method

We have studied the electronic structures in a wide temperature range for the Si(111) surface using photoemission spectroscopy combined with the laser annealing method. The temperature dependence of the Si 2p surface-sensitive core level photoemission spectra shows some gradual changes along with the thermal broadening above ~1063 K. In addition, the spectral change in the valence band photoemission spectra was also observed across the 7 × 7–1 × 1 transition temperature. These results indicate that the surface band structure is changed along with structural change at the 7 × 7–1 × 1 transition temperature. With increase of the temperature, the shift of the Si 2p core-level photoemission spectra to the lower binding energy side was observed. We discuss the temperature-induced effects such as the thermal broadening and the observed shift.

The Effect of Oxygen Exposure on Pentacene Thin Film Electronic Structure

2005 ◽  
Vol 871 ◽  
Author(s):  
A. Vollmer ◽  
O. D. Jurchescu ◽  
I. Arfaoui ◽  
I. Salzmann ◽  
T. T. M. Palstra ◽  
...  
Keyword(s):  
Thin Film ◽  
Electronic Structure ◽  
Photoelectron Spectroscopy ◽  
Hole Injection ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Air Exposure ◽  
Oxygen Exposure ◽  
Effect Of Oxygen ◽  
P Type ◽  
Injection Barrier

AbstractWe use ultraviolet photoelectron spectroscopy to investigate the effect of oxygen and air exposure on the electronic structure of pentacene thin films. It is found that O2 and water do not react noticeably with pentacene, whereas singlet oxygen/ozone readily oxidize the organic compound. Also, we obtain no evidence for considerable p-type doping of pentacene by O2 at low pressure. However, oxygen exposure lowers the hole injection barrier at the interface between Au and pentacene by 0.25 eV, presumably due to a modification of the Au surface.

Effective performance improvement of organic thin film transistors with multi-layer modifications

2020 ◽  
Vol 91 (3) ◽  
pp. 30201
Author(s):  
Hang Yu ◽  
Jianlin Zhou ◽  
Yuanyuan Hao ◽  
Yao Ni
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
Performance Enhancement ◽  
Organic Thin Film Transistors ◽  
Electrical Performance ◽  
Hole Injection ◽  
Organic Thin Film ◽  
Effective Performance ◽  
Significant Performance ◽  
P Type

Organic thin film transistors (OTFTs) based on dioctylbenzothienobenzothiophene (C8BTBT) and copper (Cu) electrodes were fabricated. For improving the electrical performance of the original devices, the different modifications were attempted to insert in three different positions including semiconductor/electrode interface, semiconductor bulk inside and semiconductor/insulator interface. In detail, 4,4′,4′′-tris[3-methylpheny(phenyl)amino] triphenylamine (m-MTDATA) was applied between C8BTBTand Cu electrodes as hole injection layer (HIL). Moreover, the fluorinated copper phthalo-cyanine (F16CuPc) was inserted in C8BTBT/SiO2 interface to form F16CuPc/C8BTBT heterojunction or C8BTBT bulk to form C8BTBT/F16CuPc/C8BTBT sandwich configuration. Our experiment shows that, the sandwich structured OTFTs have a significant performance enhancement when appropriate thickness modification is chosen, comparing with original C8BTBT devices. Then, even the low work function metal Cu was applied, a normal p-type operate-mode C8BTBT-OTFT with mobility as high as 2.56 cm2/Vs has been fabricated.

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