Research Highlights

Explore these overviews of our recent research projects.

2020 Research Highlights

Organic-to-Inorganic Structural Chirality Transfer and Impact on Rashba-Dresselhaus Spin-Splitting in 2D Perovskites »

The ability to break structural symmetry using chirality transfer from one structural unit to another provides a synthetic design paradigm for emergent properties, including spin-polarization for hybrid perovskite spintronics and related applications.

Sept. 17, 2020

Highly Distorted Chiral Tin-Iodide with Spin Polarized Transport »

Oriented organic molecules within the 2D hybrid perovskite system can induce new functionality.

June 30, 2020

Resolving Spatial and Energetic Distributions of Trap States in Metal Halide Perovskite Solar Cells »

Polycrystalline perovskite solar cell efficiencies can be improved by reducing both the surface and bulk trap densities.

March 20, 2020

Charge Carrier Transport through Ferroelastic Twin Boundaries in Halide Perovskite »

The twin boundaries formation does not decrease the device efficiency but can make perovskite electronic devices more flexible.

May 5, 2020

Ultrafast Reaction Mechanism in Perovskite Bases Photocatalytic C-C Coupling »

Photoexcited perovskite nanocrystals (NCs) can initiate photo-redox reactions by reducing and oxidization various substrates on ultrafast timescale.

Jan. 21, 2020

Circular Photogalvanic Spectroscopy of the Giant Rashba Splitting in 2D Hybrid Organic-Inorganic Perovskites »

Measurements of the Rashba splitting is an essential component of controlling Rashba splitting.

Jan. 16, 2020

2019 Research Highlights

Intense Broadband Emission in Layered Perovskites »

Broadband emission in Ruddlesden-Popper lead iodide perovskites can be induced through cation impurity atom doping and/or alloying.

Dec. 27, 2019

Negative Surface Energy for Stabilization »

The quantum confinement properties enabled by colloidal nanocrystal synthesis not only offer the opportunity to tune the light emission wavelength but can also be used to understand basic properties fundamental properties.

Dec. 18, 2019

Efficient Blue Perovskite Light-Emitting Diodes via Photoluminescence Enhancement »

Matching electron and hole current achieves record external quantum efficiency of 11% and brightness of 9040 cd/m2 in the YCl3 incorporated blue perovskite light-emitting diodes.

Dec. 10, 2019 

Spin-Dependent Charge Transport through 2D Chiral Hybrid Perovskite Layers »

Here we demonstrate how to integrate an oriented chiral organic sublattice into an inorganic framework, creating a semiconducting chiral system that can transport electrons with the desired spin control.

Dec. 6, 2019

Separating Electron and Hole Mobility in 3D Metal-Halide Perovskite »

Here we combine two methods—transient reflectance spectroscopy and terahertz spectroscopy—to detect both the electron and hole mobilities.

Nov. 21, 2019

Enhancing Electron Diffusion Length in Narrow Bandgap Perovskites for Efficient All-Perovskite Tandem Solar Cells »

This work provides a promising method to enhance the optoelectronic properties of narrow-bandgap perovskites, which unlock the potential of high-efficiency, low-cost, and solution-processable perovskite-perovskite tandem solar cells.

Oct. 3, 2019

Lead Halide Perovskites for Photocatalytic Organic Synthesis »

Low-cost, easy-to-process, highly efficient, air-tolerant, and bandedge-tunable perovskites may bring new breakthroughs in organic chemistry photocatalysis.

June 28, 2019

Perovskite Heterojunction Quantum Dot Films with Charge-Separating Interface »

Metal halide perovskite semiconductors, with chemical composition ABX3, possess outstanding characteristics for optoelectronic applications, including but not limited to photovoltaics.

June 28, 2019

Rapid Charge-Transfer Cascade through SWCNT composites Enabling Low-Voltage Losses for Perovskite Solar Cells »

By comparing the charge transfer interface between single-walled carbon nanotubes and perovskite layers in multiple different configurations, we find that the charge transport characteristics of the secondary charge-collecting layer is pivotal to achieving low interfacial recombination and the resulting high VOC.

June 20, 2019

Tunable Self-Assembling Organic-Inorganic Quantum Wells »

Films deposited by resonant-infrared matrix-assisted pulsed laser evaporation enable transient absorption spectroscopy measurements on oligothiophene-based lead halide perovskites, providing a critical window into excited state dynamics and validating hybrid density functional theory predictions of quantum well alignment between the various inorganic/organic moieties.

May 16, 2019

Exciton Fine Structure in CsPbBr3 Nanocrystals »

No other known semiconductor system has the lowest energy state being bright implying that these systems are ideal for applications that require fast and bright radiative emission.

May 15, 2019

Conductivity Tuning via Doping with Electron Donating and Withdrawing Molecules in Perovskite CsPbl3 Nanocrystal Films »

Enhanced conductivity for p-type nanocrystal (NC) arrays enables significant improvements to field-effect transistors and phototransistors, which should, in turn, lead to performance improvements in light-detecting applications and solar cells.

May 10, 2019 

Carrier Lifetimes of >1 ms in Sn-Pb Perovskites Enable Efficient All-Perovskite Tandem Solar Cells »

The addition of guanidinium thiocyanate results in marked improvements in the structural and optoelectronic properties of Sn-Pb mixed, low-band gap (~1.25- eV) perovskite films.

May 3, 2019

Enhanced Charge Transport in 2D Perovskites via Fluorination of Organic Cation »

Through fluorine substitution on the para position in phenethylammonium (PEA) to form 4-fluorophenethylammonium (F-PEA), the average phenyl ring centroid−centroid distances in the organic layer become shorter with better aligned stacking of perovskite sheets.

March 18, 2019

Sensitizing Singlet Fission with Perovskite Nanocrystals »

Singlet fission is a process that occurs in organic molecules and can enhance solar energy conversion.

March 1, 2019

Lead-Halide Perovskites for Photocatalytic C-C bond Formation »

The as-prepared perovskite nanocrystals are effective in photocatalysis with a turnover number of over 52,000 for a-alkylation, three orders of magnitude higher than precious Ir or Ru catalysts.

Jan. 2, 2019

2018 Research Highlights

Mechanism of Enhanced Broadband Emission »

Lattice distortion promotes a self-trapped exciton that emits broadband white light with a very high efficiency.

Nov. 7, 2018

Spin-Coherence Time as a Function of Layer Thickness »

In addition to larger structural distortion in 2D layered systems, there is a larger phonon coupling to carriers. These two effects can counterbalance each other to produce the longest live spin-coherence lifetime in a layered system where the layers contain 4 PbI62- octahedra.

Aug. 28, 2018