From Event: SPIE Organic Photonics + Electronics, 2017
We demonstrate enhanced photoluminescence (PL) from an optically pumped bias driven molecular tunneling junction (Au-substrate/self assembled molecular monolayer/Au-tip) with molecules chemically bound to the Au substrate. The gap between a sharp gold tip and a flat gold substrate covered with a self-assembled monolayer (SAM) of 5-chloro-2 mercaptobenzothiazole (Cl-MBT) molecules can be used as an extremely small optical gain medium. When a bias-voltage is applied between tip and sample such that electrons tunnel from the Cl-MBT’s highest occupied molecular orbital (HOMO) to the tip, holes are left behind in the molecules. These can be repopulated by hot electrons that are created by the laser-driven plasmon oscillation on the metal surfaces enclosing the molecule. Emission of photons occurs from the recombination of plasmon excited hot electrons with holes in the HOMO of surface bound molecules below the tip. Varying the laser pump power or alternatively the applied bias voltage shows in both cases a distinct threshold above which enhancement of the optical signal occurs. Solving the rate equations for this system shows that optical feed-back by the gap mode’s near field can efficiently stimulate the emission process. The system reflects many essential features of a superluminescent organic light emitting diode.
Alfred J. Meixner, Kai Braun, Xiao Wang, and Dai Zhang, "Enhanced photoluminescence from a molecular tunneling junction (Conference Presentation)," Proc. SPIE 10362, Organic Light Emitting Materials and Devices XXI, 1036207 (Presented at SPIE Organic Photonics + Electronics: August 06, 2017; Published: 19 September 2017); https://doi.org/10.1117/12.2274408.5581140205001.
Conference Presentations are recordings of oral presentations given at SPIE conferences and published as part of the conference proceedings. They include the speaker's narration along with a video recording of the presentation slides and animations. Many conference presentations also include full-text papers. Search and browse our growing collection of more than 12,000 conference presentations, including many plenary and keynote presentations.