Zhixiong Yin

Etch Dielectric

Ensure that the lab operates in a safe manner at all times by maintaining an adequate supply of waste labels, manifest forms, and empty waste buckets/bottles. Attend monthly lab safety meetings led by Keith McIntyre, the Senior Facilities Engineer for Materials Science and Engineering (MSE), to stay updated on safety protocols. Prepare hazardous waste for pickup by the Environment, Health & Safety (EHS) department and regularly review and update lab safety and waste management procedures to ensure ongoing compliance and safety.

1.Studying the transport and electric properties of thermoelectric material • Conducted synthesis and characterization of Cu2Se/CuMSe2 (M = Ga, Cr, Al) and Cu2Se/Cu4TiSe4 systems using solid-state reaction techniques. Investigated their crystal structure, thermoelectric, nano/macro-structural, and photoelectrical properties using X-ray diffraction, Physical Property Measurement System (PPMS), Transmission Electron Microscopy (TEM), and Ultraviolet-Visible Spectrophotometer (UV-Vis). • Explored carrier concentration and mobility using a high-temperature Hall coefficient measurement system and low-temperature PPMS. Developed theoretical models to fit the carrier mobility-temperature relationship. • Investigated the thermal conductivity of complex composite semiconductors and studied theoretical frameworks to explain the composition-thermal conductivity relationship. • Analyzed the nano/microstructure of Cu2Se/CuMSe2 using Backscattered Electrons (BSE) and explored the microstructural origins based on Molecular Dynamics (MD) simulation results. 2. Introduce Zinc telluride into Cadmium telluride solar cell film (Project from First Solar, Inc.) • Utilize cation exchange and solid-state reaction methods to introduce zinc ions into cadmium telluride. Verify the cation exchange results using X-ray Photoelectron Spectroscopy (XPS) and Energy Dispersive X-ray Spectroscopy (EDX). Analyze changes in crystal structure, lattice parameters and phase fraction after cation exchange through X-ray Diffraction (XRD). Characterize the optical properties using Raman Spectroscopy, Ultraviolet-Visible Spectrophotometer (UV-Vis) and Photoluminescence Spectroscopy. • Apply Physical Vapor Deposition (PVD) to uniformly deposit metal chloride onto cadmium telluride solar cell films to enhance the reaction process.

As a Graduate Student Instructor (GSI) for MSE 500: Materials Physics and Chemistry at the University of Michigan, I taught and assisted in a course with 45 students, composed of 70% graduate students and 30% undergraduates. The course delved into the physical properties of a wide range of materials, including crystalline and organic materials, from an electronic and atomic perspective. Significant emphasis was placed on the bonding and structure of materials within the frameworks of quantum mechanics and band theory, as well as their electrical, optical, thermal, mechanical, and magnetic properties. Through discussion sessions, lab work, and individual consultations, I helped students develop a deep understanding of these complex concepts, contributing to the course receiving a positive feedback rate of over 70%.

As a visiting scholar in Professor Zexiang Shen's research group, I conducted a computational analysis to identify the direction of rhenium atom chains using optical images. I quantitatively analyzed the relationship between RGB values and the rhenium atom chain direction, utilizing Multiple Beam Interference theory and MATLAB to explain this phenomenon.

I conducted research on the preparation and hemostatic properties of porous gelatin microspheres (PGMs) both in vitro and in vivo. I prepared PGMs using water-in-oil emulsion and freeze-drying techniques. Additionally, I performed in vivo and in vitro hemostasis experiments, as well as cytotoxicity tests using murine cells, to evaluate the effectiveness and safety of the microspheres.