Montanarella Federico, Urbonas Darius, Chadwick Luke, Moerman Pepijn G, Baesjou Patrick J, Mahrt Rainer F, van Blaaderen Alfons, Stöferle Thilo, Vanmaekelbergh Daniel
IBM Research - Zurich , Säumerstrasse 4 , 8803 Rüschlikon , Switzerland.
ACS Nano. 2018 Dec 26;12(12):12788-12794. doi: 10.1021/acsnano.8b07896. Epub 2018 Dec 14.
One of the most attractive commercial applications of semiconductor nanocrystals (NCs) is their use in lasers. Thanks to their high quantum yield, tunable optical properties, photostability, and wet-chemical processability, NCs have arisen as promising gain materials. Most of these applications, however, rely on incorporation of NCs in lasing cavities separately produced using sophisticated fabrication methods and often difficult to manipulate. Here, we present whispering gallery mode lasing in supraparticles (SPs) of self-assembled NCs. The SPs composed of NCs act as both lasing medium and cavity. Moreover, the synthesis of the SPs, based on an in-flow microfluidic device, allows precise control of the dimensions of the SPs, i.e. the size of the cavity, in the micrometer range with polydispersity as low as several percent. The SPs presented here show whispering gallery mode resonances with quality factors up to 320. Whispering gallery mode lasing is evidenced by a clear threshold behavior, coherent emission, and emission lifetime shortening due to the stimulation process.
半导体纳米晶体（NCs）最具吸引力的商业应用之一是其在激光器中的应用。由于其高量子产率、可调谐光学性质、光稳定性和湿化学可加工性，NCs已成为有前景的增益材料。然而，这些应用大多依赖于将NCs掺入使用复杂制造方法单独生产且通常难以操作的激光腔中。在此，我们展示了自组装NCs的超粒子（SPs）中的回音壁模式激光发射。由NCs组成的SPs既充当激光介质又充当腔体。此外，基于流入式微流体装置合成SPs，能够在微米范围内精确控制SPs的尺寸，即腔体的大小，多分散性低至百分之几。这里展示的SPs表现出高达320的品质因数的回音壁模式共振。回音壁模式激光发射通过清晰的阈值行为、相干发射以及由于受激过程导致的发射寿命缩短得以证明。
