Photoelectrochemistry of single-monolayer MoS₂: atomic-scale control of etching and passivation

Two-dimensional semiconductors such as monolayer MoS₂ are leading candidates for transistor channels that could be co-integrated with silicon in beyond CMOS devices. In a channel only three atoms thick, every processing step counts: wet-chemical etching and passivation can remove material layer-selectively and heal defects without the sulfur vacancies that dry etching introduces, but they need atomic-scale control across the whole wafer. That control requires understanding what happens at the MoS₂/electrolyte interface, where light, band alignment and defect states decide whether a reagent passivates the layer or dissolves it.

In this project you will study the photoelectrochemistry of MOCVD-grown MoS₂ monolayers and link interfacial charge transfer to their optical and electronic properties. You will use electrochemistry under controlled illumination (LSV, EIS, Mott–Schottky) to map band energetics, XPS to follow surface composition and band alignment, and photoluminescence to probe doping and defect passivation. In-house ultra-trace-level ICP-MS lets you count dissolution down to a millionth of a monolayer. AFM, TEM, ERDA and electrical measurements are available to support the work.

You will join the imec’s Surface and Interface Processing group in a multicultural and multidisciplinary environment. The insight you gain will feed directly into processes that device engineers use to build next-generation transistors.