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Search Publications by: Edwin J. Heilweil (Assoc)

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Displaying 1 - 25 of 261

Studies of spatial uniformity and jitter in SiC UV SPADs

June 15, 2023
Author(s)
Joshua Bienfang, Edwin J. Heilweil, Anand Sampath, Gregory Garrett, Jonathan Shuster, Jeremy Smith, Michael Derenge, Daniel Habersat, Reza Gandhi, Sergei Dolinsky, Enrico Bellotti, michael wrabeck
Ultraviolet single-photon avalanche detectors (UV-SPAD) that are low cost, size, weight, and power as well as resilient to shock, high temperatures and stray magnetic fields have a number of applications. SiC is attractive for UV SPADs as it is inherently

Predicting solar cell performance from terahertz and microwave spectroscopy

February 26, 2022
Author(s)
Hannes Hempel, Edwin J. Heilweil, Timothy Magnanelli
Mobilities and lifetimes of photogenerated charge carriers are core properties of photovoltaic materials and can both be characterized by contactless terahertz or microwave measurements. Previously reported values for lead-halide perovskites vary by orders

Unraveling the compositional heterogeneity and carrier dynamics of alkali cation doped 3D/2D perovskites with improved stability

December 11, 2020
Author(s)
Ming Chun Tang, Siyuan Zhang, Nhan V. Nguyen, Edwin J. Heilweil, Christina A. Hacker, Timothy J. Magnanelli, Thomas D. Anthopoulos
Preventing the degradation of hybrid perovskite by humid air remains a challenge for their future commercial utilization. 3D/2D perovskites with hierarchical architecture have attracted significant attention due to their promising power conversion

Efficient hybrid mixed-ion perovskite photovoltaics: in situ diagnostics of the roles of cesium and potassium alkali cation addition

June 19, 2020
Author(s)
Ming Chun Tang, Yuanyuan Fan, Dounya Barrit, Ruipeng Li, Hoang X. Dang, Siyuan Zhang, Timothy J. Magnanelli, Nhan V. Nguyen, Edwin J. Heilweil, Christina A. Hacker, Detlet-M Smilgies, Kui Zhao, Aram Amassian, Thomas D. Anthopoulos
Perovskite photovoltaics have made extraordinary progress in efficiency and stability in the past few years owing to process and formulation developments like antisolvent drip and mixed-cation mixed-halide compositions. Perovskite solar cells performance

Polarization Dependence of Charge Conduction in Conjugated Polymer Films Investigated with Time- Resolved Terahertz Spectroscopy

March 6, 2020
Author(s)
Timothy J. Magnanelli, Sebastian Engmann, Jared K. Wahlstrand, John C. Stephenson, Lee J. Richter, Edwin J. Heilweil
We interrogate polarization anisotropy associated with charge conduction in films of the block co polymer PCDTPT, consisting of alternating cyclopenta dithiophene (donor) and thiadiazolo pyridine (acceptor) units with respect to sample morphology. Film

Carrier mobility of silicon by sub-bandgap time-resolved terahertz spectroscopy

February 26, 2020
Author(s)
Timothy J. Magnanelli, Edwin J. Heilweil
Low density charge mobility from below bandgap, two-photon photoexcitation of bulk Silicon (Si) is interrogated using time-resolved terahertz spectroscopy (TRTS). Total charge mobility is measured as a function of excitation frequency and fluence (charge

Photodynamics of [FeFe]-Hydrogenase Model Compounds with Bidentate Heterocyclic Ligands

July 23, 2019
Author(s)
Wyatt Thornley, Sarah Wirick, Maximilian Riedel-Topper, Nathan J. DeYonker, Thomas E. Bitterwolf, Christopher J. Stromberg, Edwin J. Heilweil
Two asymmetrically structured model compounds for the hydrogen-generating [Fe-Fe]-hydrogenase active site were investigated to determine the ultrafast photodynamics, structural intermediates, and photoproducts compared to more common symmetric di-iron