CAFE’s REU Faculty and Projects

Siddharth Rajan

The objective of this project is to investigate plasma etching processes in wide and ultra-wide bandgap semiconductors. Plasma processes are a critical tool for the realization of 3-dimensional electronic and photonic devices. In this project, we will investigate the design of plasma processes to realize GaN and AlGaN fins and rods with specific geometrical properties such as aspect ratio and inclination angle. Furthermore, we will study the impact of the etching conditions on the electronic and optical properties of the materials using transport measurements, photoluminescence, and electroluminescence measurements. The project will involve semiconductor fabrication in the Nanotech West clean room, and electrical/optical measurements.

Rajan Group | At The Ohio State University (osu.edu)

Fengyuan Yang

Fengyuan Yang’s group in the Physics Department at Ohio State has a research project on growth of epitaxial perovskite dielectric and ferroelectric films on various substrates including semiconductor materials and the investigation of their structural, dielectric, and ferroelectric properties as well as their interactions with semiconductor device structures.

Yang Group | Novel Magnetism and Spintronics in Epitaxial Structures of Complex Materials (osu.edu)

Rashmi Jha

Two-Dimensional Transition Metal Dichalcogenides (TMD) materials have caught significant attention as channel materials for the next generation of scaled logic devices in stacked nanosheet configuration. However, these channel materials need to be integrated with appropriate high-k and metal gate materials with low interface trap density to meet the required performance. In this project, students will learn about various types of emerging logic and memory device configurations, role of emerging 2D materials beyond MoS2, and identifying TMD/High-k combination that best suits the performance, threshold voltage control and data storage by integrating electrically reconfigurable ferroelectric materials in the advanced transistor gate stacks, and their process-integration approaches with CMOS. Student can work in MIND Lab which is state of the art Semiconductor fabrication and testing facility at the University of Cincinnati. Alternatively, students can work at Nanotech West Lab at Ohio State University and fabricate samples collaboratively.

Lab Webpage: https://eecs.ceas.uc.edu/MIND

Eric Stinaff

New two-dimensional (2D) materials are consistently being reported with exceptional characteristics such as high mobilities, semiconducting and superconducting behavior, and excellent thermal properties. Additionally, many of these materials exhibit optical control of the spin and valley quantum degrees of freedom which may provide novel material-enabled functions in emerging areas such as spintronics and/or valleytronics. Our group uses chemical vapor deposition techniques, including a new process developed in our lab, for creating as-grown self-contacted 2D materials-based devices with the potential for tuning the properties of the resulting material. The student working on this project will gain experience in aspects of photolithography, metal deposition, CVD growth, and standard characterization techniques including photoluminescence, Raman spectroscopy, and electrical transport measurements.

PI: Eric Stinaff, Ohio University, https://people.ohio.edu/stinaff/

Roland Kawakami

Computers and smartphones we use daily are powered by transistors, small silicon-based switches that give computers their computational power. Two-dimensional semiconductors such as transition metal dichalcogenide (TMD) MoSe2 and WSe2 offer potential miniaturization and tunability beyond what

traditional silicon-based devices provide. We are investigating TMDs prepared by molecular beam epitaxy (MBE) and mechanical exfoliation to evaluate their performance as channel materials in field effect transistors (FETs). The undergraduate researcher will prepare TMDs and TMD heterostructures by means of mechanical exfoliation and dry transfer. They will assess the material quality through optical characterization and become responsible for a variety of measurements including photoluminescence, Raman, and reflectance spectroscopy. The undergraduate will characterize both exfoliated materials and thin films grown by MBE, contributing to the development of high-quality channel materials for use in FETs.

Kawakami Group | Spin, Magnetism, and Quantum Science at the Atomic Scale (osu.edu)

Sanjay Krishna

Our team is collaborating with Intel to advance Si-photonics technology by integrating III-V compound semiconductors into the Si platform. These components are vital for the upcoming generation of high-speed optical communication and remote sensing systems.

We are seeking undergraduate students interested in characterizing the optical and electrical properties of III-V/Si integrated photodetectors. The undergraduate research role involves supporting and assisting in the testing and analysis of the integrated materials/devices. This will be done using optical spectroscopy techniques, such as photoluminescence and lifetime measurement, as well as electrical characterizations through current-voltage and capacitance-voltage measurements, complemented by device modeling.

The undergrad students will work closely with Principal Investigators (PIs) and graduate students, collaborating with a team that includes four professors and five graduate students to develop new skills and knowledge. The project aims to provide undergraduate researchers with the chance to understand the fundamental science and physics of semiconductors and to tackle real-world technological challenges in advanced engineering applications. This experience is intended to create a clear path for undergraduate researchers to further their studies in graduate programs (Ph.D. or M.S.) after graduation.

Krishna Infrared Detector K.I.N.D. Laboratory | Electrical & Computer Engineering (osu.edu)

Transistors are the semiconductor devices within a computer chip that perform the switching operations that underlies their functionality. Traditionally, increasing miniaturization with only moderate modifications in materials and structure has for many decades provided the continuing performance improvements that were described by Moore’s Law. By now, traditional silicon-based device technology has reached the physical limits, and new materials and structures are explored to push beyond. In this project, the COMSOL software is used to investigate if 2D semiconductor films such as MoS2 can form field effect transistors with better characteristics than traditional silicon devices.

Lab: Windl Group | Materials Science and Engineering (osu.edu)

The undergrad researcher will support/assist one of the following three tasks by working closely with PIs and graduate students: 1) Material growth and characterization 2) Transfer III-V optoelectronic devices on Si wafers 3) Defect characterizations at the interface between III-V and Si materials. The student will largely collaborate with all group members including 4 professors (PIs) and 5 graduate students to acquire new skills and knowledge. This project aims to give undergraduate researchers the opportunity to learn about the fundamental science/physics of semiconductors as well as identify real-world challenges in the relevant technologies for advanced engineering applications. This will be a well-defined pathway for undergrad researchers to pursue graduate studies (Ph.D./M.S) after their graduation.

Lab: Krishna Infrared Detector K.I.N.D. Laboratory | Electrical & Computer Engineering (osu.edu)

Integrated optics and photonics involves the manipulation of light at the micrometer and nanometer scales. It is analogous to integrated electronics. Instead of electrons, however, photons are guided and controlled on the surface of an optical chip for the purpose of achieving high-performance optical systems with advantages in efficiency, miniaturization, mechanical stability, and economies of scale. In the project, students will perform research investigations involving design, modeling, and test of novel integrated optics and photonics devices involving wafer bonded materials for classical and quantum applications.

Websites: https://u.osu.edu/reano.1/ and https://quantum.osu.edu

Research projects within my lab cover a broad range of disciplines, including electrical & computer engineering, chemistry, physics, materials science & engineering. An undergraduate student can choose to work on the theory that drives the development of new photonic materials and devices that will enable telecom and datacom applications. My lab also works on integrating these new materials into devices at both the nano- & macro-scale.

Through the REU program, an undergraduates will be involved in fundamental and applied science of exotic and novel materials and next-generation optoelectronics that move toward a new generation of high-performance photodetectors during the Fall ’23 and Spring ’24 semesters. Projects range from device design, material growth, material characterization, device fabrication in the cleanroom and device testing. During the semester-long program, the undergraduate will conduct experimental /theoretical/ computational research projects and collaborate with six graduate students. The student will have an opportunity to get direct hands-on responsibility for theoretical prediction, numerical modeling, high quality data acquisition, reporting, analysis, and interpretation.

PI: Shamsul Arafin, arafin.1@osu.edu. Website: https://ece.osu.edu/optics-and-photonics-research-lab-oprel

Wide bandgap semiconductors like Gallium Nitride are enabling a new generation power and high-frequency electronics. The objective of this project will be to design, fabricate, and measure state-of-art electronic devices based on wide bandgap Gallium Nitride semiconductor technology.. Apply if you are a talented and motivated undergraduate student in sciences or engineering who is interested in doing advanced research. The project is multidisciplinary, and your role can be tailored to your experience and technical background/major. You will join a team that is solving some of the toughest engineering challenges in microelectronics and semiconductors!

Siddharth Rajan, Professor, ECE and MSE Departments

Website: nano.osu.edu

The computers we use in everyday life are powered by transistors, small silicon-based switches that give computers their computational power. Two-dimensional materials such as Transition Metal Dichalcogenides (TMDs) offer potential scalability and tunability beyond what traditional silicon-based devices provide. We are growing MoSe₂ and WSe₂ by Molecular Beam Epitaxy (MBE) in order to evaluate their performance as channel materials in Field Effect Transistors. The undergraduate researcher will have the opportunity to gain experience in the preparation of TMDs by MBE and mechanical exfoliation, characterization of thin films, and device fabrication and testing.

Kawakami Group | Spin, Magnetism, and Quantum Science at the Atomic Scale (osu.edu)