Selection of Metal–Tellurium (M–Te) Alloy as Recyclable Controlled Te Precursors for Wafer‐Scale Synthesis of MxTey Thin Films

Why It Matters

Enables high‑quality, scalable production of telluride semiconductors, cutting material waste and lowering manufacturing costs for next‑generation electronic and optoelectronic devices.

Key Takeaways

• Au‑Te alloy provides stable tellurium flux for wafer‑scale growth
• Recyclable alloy source reduces tellurium waste and process cost
• 4‑inch Si2Te3 films achieved, largest reported to date
• Film thickness controllable by adjusting Au/Te ratio
• Method successfully applied to MoTe2 and Cr2Te3

Pulse Analysis

Tellurium’s high volatility has long limited the commercial rollout of metal‑telluride semiconductors, which are prized for their unique electronic and thermoelectric properties. Traditional vapor‑phase methods struggle to maintain a uniform Te supply across large substrates, leading to defects and poor reproducibility. By embedding tellurium within a solid‑state metal‑tellurium alloy, the new confined tellurization process creates a localized, controllable Te reservoir that releases the element at a steady rate during film growth, overcoming the volatility bottleneck and enabling wafer‑scale uniformity.

The researchers combined first‑principles cohesive‑energy screening with systematic experiments to pinpoint alloy compositions that balance Te release with structural stability. Au‑Te and Ag‑Te alloys emerged as ideal candidates: their moderate cohesive energies prevent premature delamination of the metal/Te bilayer and suppress unwanted co‑evaporation of the host metal, problems observed with Pt, Mo, Cu, In, and Zn. Adjusting the Au‑to‑Te atomic ratio directly modulates the Te flux, giving precise control over film thickness without sacrificing crystal quality. This tunability was demonstrated by growing atomically smooth, single‑crystalline Si2Te3 films spanning four inches—setting a new size benchmark for the material.

Beyond Si2Te3, the alloy‑based approach proved versatile, successfully synthesizing MoTe2 and Cr2Te3 with comparable uniformity. Crucially, the M‑Te source is recyclable; after a growth cycle, tellurium can be replenished, dramatically reducing material waste and operational costs. This recyclable, scalable platform positions metal tellurides for broader adoption in high‑performance transistors, photodetectors, and thermoelectric generators, accelerating their transition from laboratory curiosities to industrial mainstays.