Near-Infrared Lasing from Small-Molecule Organic Hemispheres

• DOI: 10.1021/jacs.5b03051
• Publication Date: 2015-07-07T17:39:41Z
• Authors: Xuedong Wang; Qing Liao; Hui Li; Shuming Bai; Yishi Wu; Xiaomei Lu; Huaiyuan Hu; Qiang Shi; Hongbing Fu
• Keywords: Population inversion; Organic semiconductor

Near-infrared (NIR) lasers are key components for applications, such as telecommunication, spectroscopy, display, and biomedical tissue imaging. Inorganic III-V semiconductor (GaAs) NIR have achieved great successes but require expensive sophisticated device fabrication techniques. Organic semiconductors exhibit chemically tunable optoelectronic properties together with self-assembling features that well suitable low-temperature solution processing. Major blocks in realizing organic lasing include low stimulated emission of narrow-bandgap molecules due to fast nonradiative decay exciton-exciton annihilation, which is considered a main loss channel population inversion under high carrier densities. Here we designed synthesized the small molecule (E)-3-(4-(di-p-tolylamino)phenyl)-1-(1-hydroxynaphthalen-2-yl)prop-2-en-1-one (DPHP) amphiphilic nature, elaborately self-assembles into micrometer-sized hemispheres simultaneously serves medium photoluminescence quantum efficiency ∼15.2%, high-Q (∼1.4 × 10(3)) whispering gallery mode microcavity. Moreover, radiative rate DPHP enhanced up ∼1.98 10(9) s(-1) on account exciton-vibrational coupling solid state J-type molecular-coupling component, meanwhile annihilation process eliminated. As result, threshold ∼610 nJ/cm(2) single hemisphere at room temperature. Our demonstration major step toward incorporating coherent light sources compact devices wavelengths.