82 citations · 256 across the 18 of their papers we have counts for
18 papers
Atomic-Scale Observation of Symmetry Breaking in Altermagnetic MnTe
Guodong Ren, Jonathan M. DeStefano, Xiao-Wei Zhang +20
The recent discovery of altermagnetism has sparked growing interest in compensated magnetic systems as promising platforms for highly scalable spintronics. Altermagnetism is a dist…
Degradation Dynamics of Perovskite Solar Cells Under Fixed Reverse Current Injection
Fangyuan Jiang, Haruka Koizumi, Hannah Contreras +8
Previous studies of reverse-bias stability in perovskite solar cells have focused primarily on voltage controlled reverse-bias tests. Here we instead present an investigation of pe…
pH Regulates Ion Dynamics in Carboxylated Mixed Conductors
Zeyuan Sun, Mengting Sun, Rajiv Giridharagopal +12
Coupled ionic and electronic transport underpins processes as diverse as electrochemical energy conversion, biological signaling, and soft adaptive electronics. Yet, how chemical e…
Deposition-Dependent Coverage and Performance of Phosphonic Acid Interface Modifiers in Halide Perovskite Optoelectronics
Hannah Contreras, Aidan O'Brien, Margherita Taddei +10
In this work, we study the effect of various deposition methods for phosphonic acid interface modifiers commonly pursued as self-assembled monolayers in high-performance metal hali…
Multi-Output Convolutional Neural Network for Improved Parameter Extraction in Time-Resolved Electrostatic Force Microscopy Data
Madeleine D. Breshears, Rajiv Giridharagopal, David S. Ginger
Time-resolved scanning probe microscopy methods, like time-resolved electrostatic force microscopy (trEFM), enable imaging of dynamic processes ranging from ion motion in batteries…
Sub-diffraction Imaging of Carrier Dynamics in Halide Perovskite Semiconductors: Effects of Passivation, Morphology, and Ion Motion
Madeleine D. Breshears, Justin Pothoof, Rajiv Giridharagopal +1
We spatially resolve photocarrier dynamics in halide perovskites using time-resolved electrostatic force microscopy (trEFM) to map surface potential equilibration during photoexcit…
Optical tuning of the diamond Fermi level measured by correlated scanning probe microscopy and quantum defect spectroscopy
Christian Pederson, Rajiv Giridharagopal, Fang Zhao +4
Quantum technologies based on quantum point defects in crystals require control over the defect charge state. Here we tune the charge state of shallow nitrogen-vacancy and silicon-…
Kinetic Suppression of Photoinduced Halide Migration in Wide Bandgap Perovskites via Surface Passivation
Farhad Akrami, Fangyuan Jiang, Rajiv Giridharagopal +1
In this work, we study the kinetics of photoinduced halide migration in FACsPb(IBr) wide (~1.69 eV) bandgap perovskites and show halide migratio…
Why accumulation mode organic electrochemical transistors turn off much faster than they turn on
Jiajie Guo, Shinya E. Chen, Rajiv Giridharagopa +7
Understanding the factors underpinning device switching times is crucial for the implementation of organic electrochemical transistors (OECTs) in neuromorphic computing and real-ti…
Surface Passivation Suppresses Local Ion Motion in Halide Perovskites
Justin Pothoof, Robert J. E. Westbrook, Rajiv Giridharagopal +2
We use scanning probe microscopy to study ion migration in the formamidinium (FA)-containing halide perovskite semiconductor in the pres…
Hydration of a side-chain-free n-type semiconducting ladder polymer driven by electrochemical doping
Jiajie Guo, Lucas Q. Flagg, Duyen K. Tran +7
We study the organic electrochemical transistors (OECTs) performance of the ladder polymer, poly(benzimidazobenzophenanthroline) (BBL) in an attempt to better understand how an app…
(3-Aminopropyl)trimethoxysilane Surface Passivation Improves Perovskite Solar Cell Performance by Reducing Surface Recombination Velocity
Yangwei Shi, Esteban Rojas-Gatjens, Jian Wang +8
We demonstrate reduced surface recombination velocity (SRV) and enhanced power-conversion efficiency (PCE) in mixed-cation mixed-halide perovskite solar cells by using (3-aminoprop…
Extraction of instantaneous frequencies and amplitudes in nonstationary time-series data
Daniel E. Shea, Rajiv Giridharagopal, David S. Ginger +2
Time-series analysis is critical for a diversity of applications in science and engineering. By leveraging the strengths of modern gradient descent algorithms, the Fourier transfor…
Bismuth-doping Alters Structural Phase Transitions in Methylammonium Lead Tribromide Single Crystals
Erin Jedlicka, Jian Wang, Joshua Mutch +8
We study the effects of bismuth doping on the crystal structure and phase transitions in single crystals of the perovskite semiconductor methylammonium lead tribromide, MAPbBr3. By…
Imaging graphene moiré superlattices via scanning Kelvin probe microscopy
Junxi Yu, Rajiv Giridharagopal, Yuhao Li +5
Moiré superlattices in van der Waals heterostructures are gaining increasing attention because they offer new opportunities to tailor and explore unique electronic phenomena when s…
Sn4+ Precursor Enables 12.4% Efficient Kesterite Solar Cell from DMSO Solution with Open Circuit Voltage Deficit Below 0.30 V
Yuancai Gong, Yifan Zhang, Erin Jedlicka +12
The limiting factor preventing kesterite (CZTSSe) thin film solar cell performance further improvement is the large open-circuit voltage deficit (Voc,def) issue, which is 0.345V fo…
Noncontact Imaging of Ion Dynamics in Polymer Electrolytes with Time-Resolved Electrostatic Force Microscopy
Jeffrey S. Harrison, Dean A. Waldow, Phillip A. Cox +7
Ionic transport processes govern performance in many classic and emerging devices, ranging from battery storage to modern mixed-conduction electrochemical transistors. Here, we stu…
Interfacial charge transfer in nanoscale polymer transistors
J. H. Worne, R. Giridharagopal, K. F. Kelly +1
Interfacial charge transfer plays an essential role in establishing the relative alignment of the metal Fermi level and the energy bands of organic semiconductors. While the detail…