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Program Highlights

What happens to photogenerated charges in semiconductor nanowires?

July 6, 2016
How? We use optical microscopy to determine the dynamics of photo-generated charges in individual semiconductor nanowire hetero-structures.

Development of chemical and biological sensors: Synthesis of Plasmonic Nanoparticles and Multispectral Imaging Nanostructures

July 6, 2016

How? Synthesizing and isolation of ultra-small gold nanoparticles with a specific shape or structure. We have developed a facile approach for shape-controlled synthesis of gold nanoparticles using KBr and 5-hydroxyindoleacetic acid (5-HIAA) as the reducing agent. 

Investigation of Indium Free Transparent Conducting Oxides for Application in Photovoltaics

September 11, 2015

Transparent conducting oxide play a key role in photovoltaic (PV) devices. There has been much recent interest in finding alternative indium (In) free TCOs and even better performing alternative candidates to substitute for standard ITO.  The driving factors are: scarcity, unintended interfacial phenomena, rapid price increase and global politics associated with In metal in ITO. TCOs based on titanium (Ti) doped tungsten oxide (WO3) thin films were studied in this project. X-ray photoelectron spectroscopy (XPS) analyses provided the chemical and electronic structure changes in the Ti-doped WO3 thin films. The studies when combined with optical studies enabled engineering the materials with desired TCO properties.

Synthesis of Fullerene Derivatives for Potential Applications in OPV Devices

September 11, 2015

We have separated Sc3N@D5h-C80 from Sc3N@C68 based on their chemical reactivity differences using the p-toluenesulfonyl tosyl hydrazone of phenyl butyric acid methyl ester (PCBM). We also performed for the first time the synthesis and characterization of five PCBM methano-derivatives of Sc3N@D5h-C80 (including the X-ray diffraction structure of one of the isomers) and two PCBM methano-derivatives of Sc3N@C68.

We also synthesized four easily isolable regio and stereoselective pure bis-adducts of C60 and C70 and a new C70 dumbbell using two different malonate tethered moieties.

Humacao PREM visits Rural Schools

August 5, 2015

In March-April 2015, approximately 50 PREM students, faculty and other volunteers visited six rural schools in the towns of Yabucoa and San Lorenzo, Puerto Rico. The activities included short talks and hands-on demonstrations from the Nanodays (NISENet) kits and others developed by our program. Over 800 students, teachers and parents participated in this effort to reach minority and geographically isolated communities. 

 

 

Bubble formation in chloroform at negative pressures

August 5, 2015

The aim of this project if to detect and characterize nucleation sites when a local cavity starts to form, in particular to detect cavitation sites in molecular dynamics simulations of liquid chloroform with and without carbon nanotubes.

Ultraviolet Tunable MoS2/p-Silicon Junction Diode

August 4, 2015

MoS2 single crystals were transferred onto the edge of a p-Si/SiO2 wafer, forming an abrupt heterogeneous junction diode at the MoS2/p-Si interface. When electrically characterized as a field effect transistor, MoS2 exhibits an n-type response and can be doped in the presence of ultraviolet (UV) light. Its simple design coupled with the ability to rectify AC signals, sense UV light, and reversibly tune these diodes makes them inexpensive, multifunctional, and usable as active or passive components in complex electronics.




 

Hysteretic Adsorption of CO2 onto a Cu2(pzdc)2(bpy) Porous Coordination Polymer and Concomitant Framework Distortion

August 4, 2015

In a recent publication resulting from a collaboration between the IRG2 of the Wisconsin MRSEC and the University of Puerto Rico Mayaguez through the NSF-sponsored Partnerships for Research and Education in Materials (PREM) program, Prof. Hernandez-Maldonado and coworkers investigated the structural mechanisms of the hysteretic adsorption of carbon dioxide onto the porous coordination polymer, CPL-2. CPL-2 is currently under investigation for industrial-scale carbon dioxide capture applications.

Combination treatment with synthetic β-peptide enhances the antifungal activities of azoles in Candida albicans

August 4, 2015

Fungal infections such as candidiasis represent an important human health concern worldwide due to high mortality rates, of more than 50%, specifically in those people who are immunocompromised.  In particular risk are those patients undergoing chemotherapy, that suffer from AIDS and those who receive an organ transplant.  Other concerns include the side effects of the current antifungal drugs and the emergence of multidrug resistant organisms. 

Do “Hot” Charge-Transfer Excitons Promote Free Carrier Generation?

August 4, 2015

In organic photovoltaics, the role of hot charge-transfer (CT) excitons on free carrier generation is currently under intense debate. In this project, we carry out first-principles time-dependent density functional theory calculations to examine hot CT dissociation in polymer/fullerene heterojunctions. We reveal that whether or not hot CT states promote charge separation depends on excitation spectral range and crystallinity of the donor and acceptor phases. We find that while the crystallinity of the donor phase underlies the energy dependence of CT exciton dissociation, the crystallinity of the acceptor determines charge separation efficiency. We propose a theory that can reconcile contradictory experimental observations and provide insight into hot CT dissociation. Crucially, the timescale of hot CT dissociation is found to be comparable to the timescale of its relaxation to the lowest-lying CT state, which is localized in all interfacial models studied.

 

Nanotechnology Exhibition for Junior High School Participants

August 1, 2015

NSF-JSU-UCSB PREM members conducted outreach activities at local school and initiate a Science Line program to the minority participants.

Plasmonic–Magnetic 3D Graphene Oxide Architecture Can Pick and Separate Rotavirus

August 1, 2015

According to the World Health Organization (WHO), more than 1.5 million children die each year due to rotavirus contamination in drinking water.

Nanomaterial Based Long-Range Ruler Can Screen Prostate Tumor

August 1, 2015

Since the ability to detect very low levels of prostate specific membrane antigen (PSMA) may enable doctors to diagnose men with prostate cancer recurrence, it has the capability to reduce prostate cancer-related mortality and morbidity.

Graphene Oxide Can Pick and Image MRSA

August 1, 2015
The evolvement of multiple drug resistance MRSA bacteria has increased day by day and are spread all over the world. Early diagnosis is the key for survival from MRSA infection.

PREM NMHU Highlights

July 30, 2015

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