Excimer

About: Excimer is a research topic. Over the lifetime, 3725 publications have been published within this topic receiving 75104 citations.

Intramolecular excimer emission as a blue light source in fluorescent organic light emitting diodes: a promising molecular design

Abstract: Intramolecular excimer emission arising from organic molecules as a blue light source in fluorescent Small Molecule Organic Light Emitting Diodes (SMOLEDs) is almost absent from the literature. In this work, three aryl-substituted DiSpiroFluorene–IndenoFluorenes (DSF–IFs 1–3) possessing different fluorescent properties due to their different main emitters have been investigated through a structure–property relationship study. Due to its particular geometry, the rigid DSF–IF platform 2 allows an ‘aryl/fluorene/aryl’ dimer to be preformed in the ground state leading, in the excited state, to a deep blue fluorescent emission through strong π–π intramolecular interactions between the two ‘aryl/fluorene/aryl’ arms. 2 has been successfully used as an emitting layer in a SMOLED with electroluminescence arising from electrogenerated intramolecular excimers and the properties of these excimer-based OLEDs have been compared to those of two model compounds (1 and 3). The simple and non-optimized double-layer device displays a deep blue colour (CIE coordinates: 0.19; 0.18) exhibiting a luminance of 510 Cd m−2 with a luminous efficiency of ca. 0.1 Cd A−1. This work is, to the best of our knowledge, the first rational and comparative study describing an intramolecular excimer based-SMOLED.

Excimer laser inspection system

Abstract: A system and method for inspecting a specimen, such as a semiconductor wafer, including illuminating at least a portion of the specimen using an excimer source using at least one relatively intense wavelength from the source, detecting radiation received from the illuminated portion of the specimen, analyzing the detected radiation for potential defects present in the specimen portion.

Insight into the mechanism and outcoupling enhancement of excimer-Associated white light generation

Abstract: Fundamental insight into excimer formation has been gained by using 9,10-bis[4-(9-carbazolyl)phenyl]anthracene] (Cz9PhAn) as a probe. Cz9PhAn exhibits a highly emissive blue fluorescence in solution and is found to emit a panchromatic white light spectrum (400–750 nm) in film, powder and single crystal, in which an additional excimer band appears at ∼550 nm. Detailed structural analyses, emission relaxation dynamics and a theoretical approach conclude the formation of an anthracene*/phenyl ring excimer through an overlap between π* (anthracene) and π (phenyl ring) orbitals in a face-to-edge stacking orientation. The rate of excimer formation is determined to be 2.2 × 109 s−1 at room temperature, which requires coupling with lattice motion with an activation energy of 0.44 kcal mol−1. Exploiting Cz9PhAn as a single emitter, a fluorescent white organic light emitting diode (WOLED) is fabricated with a maximum external quantum efficiency (ηext) of 3.6% at 1000 cd m−2 (4.2 V) and Commission Internationale de L'Eclairage (CIE) coordinates of (0.30, 0.33). The white-light Cz9PhAn reveals a preferred orientation of the transition dipole moment in the emitting layer to enhance light outcoupling. This non-doped, single component (Cz9PhAn) WOLED greatly reduces the complexity of the fabrication process, rendering a green and cost-effective alternative among the contemporary display/lighting technologies.