Direct Integration of 2D Materials for Next-Generation Electronic Devices

Speaker

Zakaria Al Balushi

• Assistant Professor of Materials Science and Engineering, University of California, Berkeley
• Faculty Scientist at Lawrence Berkeley National Laboratory

About This Talk

Two-dimensional (2D) semiconductors, such as molybdenum disulfide (MoS2), are emerging as key materials for next-generation electronics, addressing challenges in the miniaturization of silicon-based technologies. Despite progress in scaling-up 2D materials, integrating them into functional devices remains challenging, particularly in the context of three-dimensional integration. This talk will present a scalable method for growing high-quality mono- to few-layer MoS2 on large wafers using a spin-on precursor, molybdenum ethyl xanthate. The growth dynamics and associated versatile features are thoroughly investigated using comprehensive characterization, reactive force-field molecular dynamics simulations, and density functional theory. The method allows precise control over film thickness, grain size, and defect density, yielding wafer-scale monolayer MoS2 with reliable optical properties comparable to as-exfoliated samples. These findings highlight the versatility of spin-on metal xanthate chemistries for the synthesis and integration of transition metal dichalcogenides (MoS2, WS2, NbS2, ReS2, etc.), paving the way for advanced nanoscale fabrication processes and enhancing the commercial viability of 2D materials in electronics.

Moreover, forming heavily doped regions in two-dimensional materials, like graphene, are a stepping stone to the design of emergent devices and heterostructures. This talk will also present a selective-area approach to tune the work-function and carrier density in monolayer graphene by spatially synthesizing sub-monolayer gallium beneath the 2D-solid. 

Finally, metalorganic chemical vapor deposition (MOCVD) has become a pivotal technique for developing wafer-scale TMD 2D materials. Al Balushi will discuss recent findings on the impact of MOCVD growth conditions on achieving uniform and selective polymorph phase control of MoTe2 over large wafers. This study highlights the importance of precise control over the MOCVD growth temperature to engineer the MoTe2 phase of interest for device applications.

About the Speaker

Zakaria Al Balushi is an assistant professor in the Department of Materials Science and Engineering at University of California, Berkeley, and a faculty scientist in the Materials Science Division at the Lawrence Berkeley National Laboratory. Al Balushi received his BS (2011), MS (2012) in Engineering Science and his PhD (2017) in materials science and engineering all from Pennsylvania State University. His early work focused on integration and fabrication of silicon nanowire devices, then on the growth of group-III nitride semiconductors, in situ metrology during MOCVD growth, epitaxial graphene and the discovery and characterization of unconventional low-dimensional materials and heterostructures. Prior to his appointment at the University of California, Berkeley, he held two postdoctoral fellowships: the Resnick Prize Fellowship in Applied Physics and Materials Science and the NSF Alliances for Graduate Education and the Professoriate Fellowship, both at the California Institute of Technology under the supervision of Professor Harry Atwater. At the University of California, Berkeley, his research group continues to expand in this area and beyond, creating new synthesis and integration schemes for emerging low-dimensional materials. He is currently serves on the editorial board of Communications Materials, is an elected executive committee member for the American Association for Crystal Growth and was recently named “Four rising stars who are reshaping nanoscience” by Nature [Nature 608, S12-S13 (2022)]. He is also a SK Hynix Faculty Fellow, Society of Hellman Fellow, a CIFAR Azrieli Global Scholar in Quantum Materials and a recipient of the NSF CAREER and Micron Corporation Early Career Awards in 2022.

About the MSE Seminar Series

The Materials Science and Engineering (MSE) Seminar Series features distinguished speakers from leading institutions, offering a platform for sharing groundbreaking research, innovative ideas, and entrepreneurial experiences. Held multiple times each semester, these seminars bring global perspectives world to MIT’s materials research community, exposing students, faculty, and postdocs to cutting-edge concepts and valuable networking opportunities.