Bifacial Photovoltaic (PV) System Performance Modeling

Unlike conventional monofacial photovoltaic (PV) cells, bifacial PV cells convert light hitting the both sides of them to electricity. However, partly due to lack of accurate bifacial PV system modeling, methods to predict system performance of bifacial systems have remained limited. We are developing a model using reverse ray tracing method to accurately estimate the performance of bifacial PV systems. The model is based on RADIANCE and Python software and validated by field data. For more details on the team and project please also visit the PV Performance Modeling Collaborative's website. 

Collaborators include Dr. Josh Stein at the Sandia National Laboratories, Dr. Chris Deline at the National Renewable Energy Laboratory, and Professor Zachary Holman at Arizona State University. Funded by the U.S. Department of Energy.

High-Efficiency and Low-Cost Photovoltaic (PV) Solar Cells

We are utilizing various low-cost chemical texturing techniques to develop high efficiency silicon-based mono- and bi-facial solar cells. The team specializes in the formation of nano- and micro-textured silicon surface (often termed as black Si (bSi)) by metal assisted catalyzed etching (MACE), where the metal catalysts are copper (Cu) or silver (Ag). 

Funded by Iowa Energy Center Opportunity grant and UI Internal Funding Initiative grant. 

Nanotextured Optoelectronic Biosensors

Silicon Nanowire Arrays based Sensors 

Nanowires (NWs) are effective sensing structures due to their large surface area to volume ratio. However, contacting the NW arrays is challenging. Our silicon (Si) NW optoelectronic biosensor is made by a bundle of vertically oriented NWs, allowing us to electrically contact millions of NWs per cm² simultaneously, compared to 10’s of NWs in other state-of-the-art NW biosensors.

Collaborators on the project include, Professor Aliasger Salem's lab at UIowa, Dr. Pashtoon Kasi at the UIHC, and Dr. Marcie Black of Advanced Silicon Group. Funded by the National Science Foundation STTR and I-Corps programs, and UI GAP funding. 

Sol-gel sensors have been developed for a variety of applications. We are developing sol-gel sensors integrated with nanotextured silicon surfaces and metal nanoparticles to develop sensors for low-cost water quality monitoring. 

Collaborator on the project includes Professor Gregory LeFevre at UIowa. Funded by the Center for Health Effects of Environmental Contamination (CHEEC) and Environmental Health Sciences Research Center (EHSRC) at UIowa.

III-V Nanowire Optoelectronics

Our team’s goal is to use NWs to develop novel semiconductor optoelectronics devices, such as, photovoltaics, lasers, and LEDs. We are developing the selective area epitaxy (SAE) technique to grow III-V NWs on inexpensive silicon substrates utilizing molecular beam epitaxy. The NW carrier dynamics and optoelectronic response are characterized by ultrafast optical pump-probe spectroscopy, quantum efficiency, and  photoluminescence measurements. 

Collaborator on the project includes Professor John Prineas' lab at UIowa. Funded by the National Science Foundation Electronics, Photonics and Magnetic Devices (EPMD) program.

Metamaterials

and Metasurfaces

In this research project we are developing terahertz (THz) metamaterials with frequency-domain modulating functionality for THz spectroscopy. Being situated between infrared light and microwave radiation, the absorption of THz rays in molecular and biomolecular systems is dominated by the excitation of intramolecular and intermolecular vibrations. This indicates that THz technology is an effective tool for sensing applications. The design of the metamaterials is performed utilizing COMSOL finite element method based analytical modeling and fabricated using a novel Laser-based Metasurface Fabrication (LMF) method. The relationship between the filter design and bandpass characteristics are determined through THz spectrometer. 

Collaborator on the project includes Professor Hongtao Ding. Funded by CCAD's Research Initiative Seed Program's Genesis grant. 

Laser Medicine

In this project we are utilizing compact mid-infrared (MIR) quantum or interband cascade lasers emitting in the MIR (can be designed to emit the entire MIR range of 2.5 μm to 15 μm by quantum engineering) to treat disease. Amines, alcohols, and amides have absorption in the MIR, and they are the key components in human tissue. 

Collaborator on the project include Professor Mitch Coleman and Professor Rebecca Dodd at UIHC. Funded by UIHC's Sarcoma MOG seed funding.