English

Molecular orientation is key: a new perspective on revealing electronic behavior using two-photon emission spectroscopy

1124
2024-03-19 16:20:43
See translation

Organic electronics has aroused great interest in academia and industry due to its potential applications in OLEDs and organic solar cells, with advantages such as lightweight design, flexibility, and cost-effectiveness. These devices are made by depositing organic molecular thin films onto a substrate that serves as electrodes and exerting their effects by controlling electron transfer between the film and substrate. Therefore, understanding the electronic behavior at the interface between the substrate and the thin film, as well as the electronic properties of organic thin films, is crucial for the further development of organic electronics. In addition, simultaneous observation of photocarrier electrons and intramolecular photoexcitation will provide more insights into organic molecular thin films.

Although a technique called photoelectron spectroscopy has been used to study the static electronic states of organic molecule films in detail, accurately detecting the dynamic behavior of electrons attempting to express their functions in devices has always been challenging and hindering progress.

The research team led by Associate Professor Masahiro Shibuta from the Graduate School of Engineering at Osaka City University used two-photon emission spectroscopy, scanning tunneling microscopy, and low-energy electron diffraction to observe the electronic behavior and surface structure of triphenyl molecular thin films deposited on graphite substrates. The results indicate that TP molecules exhibit a special structure, which adsorbs on the substrate in a standing structure. Under light irradiation, two electrons are injected into TP molecules from the substrate, and photoexcited electrons in the molecular thin film are successfully observed simultaneously in a single sample. In addition, strong photoluminescence was also observed on thin films with a special structure consisting of only one layer of molecules, where the molecules were diagonally adsorbed onto the substrate, similar to the case of TP molecules. It is expected that these results will contribute to the development of new luminescent materials and the further development of functional organic electronic devices.

"2PPE spectroscopy is still a new method for evaluating electronic states, but its drawback is that although well optimized measurements are time-consuming, electronic states are sometimes well observed and sometimes not," said Professor Shibuta. Our research findings emphasize that the visibility of electronic states is closely related to the adsorption mode and electronic properties of molecules on the substrate. In other words, not only the type of molecules, but also their arrangement must be appropriately controlled to create a device that can fully demonstrate their functions. I am pleased that our research provides insights for the development of functional materials for practical applications.

Source: Laser Net

Related Recommendations
  • The University of Stuttgart has simplified the detection of nanoplastics

    Detecting the presence of nanoscale plastic particles in the environment has become a topic of concern for industrial societies worldwide, not least since particles of that size can evade the body's blood-brain barrier and damage metabolic processes.Optical technologies have been at the forefront of these monitoring efforts. Recent examples have included the use of stimulated Raman scattering to s...

    09-15
    See translation
  • Advancing Astronomy: Using Laser Guided Star Adaptive Optics to Obtain clearer celestial views

    Adaptive optics is defined as an advanced optical system used to correct the transmission medium between the subject and the image, providing users with clearer images. Adaptive optics helps to use a complex combination of deformable mirrors to correct images in real-time through distortion in the Earth's atmosphere. These images are of greater importance in many vertical industries such as health...

    2024-02-22
    See translation
  • Nikon launches COOLSHOT 20i GIII laser rangefinder with two measurement display modes: golf and actual distance

    Nikon Vision, a subsidiary of Nikon Corporation, is pleased to announce the launch of the COOLSHOT 20i GIII laser rangefinder for golfers, which is Nikon's small and lightweight model in the COOLSHOT series.While maintaining the lightweight and compact size of the COOLSHOT 20i GII, the new model notifies users through brief vibrations that the distance to the flagpole has been measured.When measur...

    2024-03-27
    See translation
  • Single photon avalanche diode for millimeter level object recognition using KIST

    LiDAR sensors are crucial for implementing modern technologies such as autonomous driving, AR/VR, and advanced driving assistance systems. For example, more accurate shape detection in AR/VR devices and smartphones depends on the improved range resolution of medium and short range LiDAR. This requires a single photon detector with improved timing jitter performance.LiDAR calculates the distance an...

    2024-02-03
    See translation
  • AMC Theatres launches advanced laser projection technology upgrades

    AMC Cinema has long been known as the largest cinema operator in the United States and the world, and has completed upgrades to almost all its venues in the broader Chicago area, including advanced laser projection technology.The technological reform of this chain of stores has made Chicago one of the first areas in AMC's footprint to benefit from CinIonic's cutting-edge projection technology.In e...

    2023-12-23
    See translation