Haichun Liu

Researcher

Experimental Biomolecular Physics

Department of Applied Physics
Royal Institute of Technology
Roslagstullsbacken 21
S-106 91 Stockholm, Sweden

Research Interest:light upconversion nanotechnology; super-resolution microscopy; perovskite quantum dots

NEWS:

2019-02-19 - Paper published online in Nanoscale.

New paper "On the decay time of upconversion luminescence" published online.  Systematically investigate the decay characteristics of upconversion luminescence through numerical simulations based on rate-equation models. Important findings are veried by experimental results. Available here.

2019-01-09 - Paper published online in Nanoscale.

New paper "Fast upconversion super-resolution microscopy with 10 μs per pixel dwell times" published online. Report an important improvement of super-resolution imaging based on upconversion nanoparticles, allowing much faster imaging speeds, with pixel dwell times of 10 us. This imaging speed is well in parity with typical pixel dwell times in nanoscopy based on organic dyes. Available here.

2018-11-27 - Letter to the Editor published online in ACS Nano.

Our Letter to the Editor "Overtone vibrational transition-induced lanthanide excited-state quenching in Yb3+/Er3+-doped upconversion nanocrystals" published online. Discuss direct solvent quenching by overtone transition to key NIR excited states in the upconversion process. Experimental evidence provided. Available here.

2017-11-17 - Paper published online in Laser & Photonics Reviews.

New review article "Photon Upconversion Kinetic Nanosystems and Their Optical Response" published online. Explore UCNPs from the outset of being kinetic optical systems and review their physical formation, underlying photophysics, macroscopic statistical description, and their response to various optical stimuli in spectral, polarization, intensity, temporal and frequency domains, and demonstrate ways that their optical output can be optimized by manipulating excitation schemes. Available here.

2017-11-10 - Paper published online in Nanoscale.

New paper "Protected excitation-energy reservoir for efficient upconversion luminescence" published online. Available here.

2017-10-20 - Paper published online in Nature Communications.

New paper "Achieving high-efficiency emission depletion nanoscopy by employing cross relaxation in upconversion nanoparticles" published online. Develops an efficient emission depletion mechanism for lanthanide upconversion nanoparticles, demenstrates two-color super-resolution imaging using UCNPs with a single pair of excitation/depletion beams, and implements for the first time super-resolution imaging of immunostained cytoskeleton structure of fixed cells with resolution of ~82 nm using UCNPs.  Available here. Our research is reported by KTH news.

2016-12-27 - Paper published online in Nanoscale.

New paper "Phase angle encoded upconversion luminescent nanocrystals for multiplexing applications" published online. Identifies and identifies the rise behavior of upconversion luminescence kinetics due to interionic energy transfer, and develops a new optical encoding dimension for upconversion nanomaterials, i.e., the phase angle of upconversion luminescence in response to a harmonic-wave excitation. Extends the multiplexing capacity of upconversion nanoparticles and offers new opportunities for their applications in a wide range such as microarray assays, bioimaging, anti-counterfeiting and deep tissue multiplexing labelling/detection.  Available here. This article is selected as part of the themed collection: 2017 Nanoscale HOT Article Collection.