Blue nanocrystal perovskite LEDs have traditionally lagged behind their red and green cousins. Here, we discuss the reasons for this lag and propose solutions to these problems, producing high efficiency blue perovskite LEDs. We demonstrate the NiOx, a transport material in one of the highest performing devices to date, reduces the performance of nanocrystals near to the interface. By replacing it with an alternative transport structure, we show that the nanocrystal emission is unperturbed. We then build full LEDs out of this transport structure, increasing the EQE from 0.03% to 0.50%, the highest for inorganic perovskite nanocrystals at this wavelength. We further show that the benefits of this transport structure relax as the energetics redshift, as our blue-green devices match those from literature. These results are a useful step forward towards commercially relevant perovskite LEDs.
Fluorescence imaging provides a powerful approach to study fundamental life processes and has become an integral part of the toolbox for biologists. In order to study molecular interactions, single molecule imaging approaches require labeling the molecules with fluorescent reporters. The influence of these fluorescent labels to the molecular interactions have been unknown. In this talk, I will present a hybrid photonic-plasmonic nano-device as a new tool to study molecular interactions at the single molecule level. By coupling a single plasmonic nanoantenna with photonic crystal nanocavity, we can achieve both high quality factor and ultra-small mode volume, thus pushing the detection limit to the single molecule level while keeping the local heating effect at a negligible level.
Fluorescence imaging provides a powerful approach to study fundamental life processes and has become an integral part of the toolbox for biologists. In this talk, I will present optical nanosensors as a new tool; and how we push it to the limit for the applications of translational medicine. Two examples will be given to represent two distinct architectures to solve medical problems at single molecule and single cell level, respectively. The first example is a “lab-on-a-chip” device that can measure binding kinetics between two single molecules without fluorescent labeling. The second example is a “lab-on-a-tip” device that monitors protein expressions in single living cells over time. These nanosensor approaches, complementary to fluorescent imaging, will broaden our understanding of basic life processes at molecular level and will provide new ways for drug discovery and disease diagnostics.
Most traditional biological assays are based on ensemble measurements on cells. Due to lack of the detection
sensitivity and efficiency in sample preparation, analyzing proteins in single cells have been challenging.
Here we describe an assay-on-a-tip platform, and demonstrate an in situ, label-free technique to detect
proteins inside single cells.
Conference Committee Involvement (3)
Biosensing and Nanomedicine XII
11 August 2019 | San Diego, California, United States
Biosensing and Nanomedicine XI
19 August 2018 | San Diego, California, United States
Biosensing and Nanomedicine X
6 August 2017 | San Diego, California, United States