Senior Diffusion Process Engineer

T1 Energy is bringing solar manufacturing back to the U.S. by building a domestic solar supply chain. Our mission is to invigorate America with scalable, reliable, and low-cost energy. Our fully operational 5GW solar module facility in Wilmer, Texas, can manufacture more than 20,000 modules every 24 hours. By the time you finish reading this paragraph, we will have produced two solar panels that will power American homes and fuel domestic AI.

We're focused on building advanced American manufacturing and we're passionate about engineering a better future filled with abundant energy.

The Role

T1 Energy is looking to hire a Thermal Process Engineer to join our team supporting the process development and ramp of our G2 solar cell fab. This is a hands-on, high-impact role for a process engineer who knows their way around diffusion toolsets and is ready to help build one of the most ambitious domestic solar manufacturing operations in the country.

You'll be working at the leading edge of solar cell manufacturing, owning critical doping thermal processes that directly impact cell efficiency, yield, and throughput. If you've spent your career developing and optimizing boron and phosphorus diffusion processes in a semiconductor or photovoltaic environment and you're ready to do it at scale, this is the role for you.

What You'll Do

• Support thermal doping process integration across the G2 solar cell fab, working closely with equipment, facility, quality, and yield engineering teams.
• Drive process characterization, design of experiments (DOE) execution, and data analysis to improve dopant uniformities and throughput.
• Troubleshoot process excursions and equipment issues on diffusion tools and sub-inspection modules, identifying root causes and implementing corrective actions.
• Collaborate with equipment engineers and tool vendors to qualify new tool integrations, execute preventive maintenance reviews, and maintain process baselines.
• Develop and maintain detailed process documentation, including recipes, SOPs, and control plans.
• Optimize process performance through statistical process control (SPC) and lead OEM work inspection development integration with urgency.
• Support technology transfer from development to high-volume manufacturing, ensuring processes are robust, repeatable, and scalable.
• Partner with cross-functional teams, including core equipment engineering, material procurement, and manufacturing operations to meet cell efficiency and production targets.
• Who You Are
• Experienced working in a cleanroom setting.
• Driven by a strong understanding of thermodynamics, transport phenomena, vacuum systems, electron-hole physics (Hall effect), and thin film characteristics.
• Deep experience working with high-temperature (500 °C+), high-volume manufacturing equipment with silicon or glass material inputs.
• Comfortable with chemical characterization, including crystal lattice chemistry, quantum field effects, and the principles of oxidation/reduction in gaseous environments, particularly as applied to photon-electron interfaces.
• Experienced with III-V, GaAs, PERC, TOPCon, or other silicon-based solar cells.
• Data-driven in your approach to process development and troubleshooting — you let the numbers lead.
• Able to work effectively in a fast-moving fab environment where priorities shift and deadlines are real.
• A strong collaborator who can work across engineering disciplines and communicate technical findings clearly to varied audiences.
• Energized by the challenge of building something new and scaling it to high-volume production.

Qualifications

• Bachelor's degree or higher in Chemical Engineering, Materials Science, Electrical Engineering, Physics, or a related field.
• 5+ years of process engineering experience in semiconductor, photovoltaic, or advanced manufacturing environments.
• Hands-on experience with high-temperature diffusion toolsets.
• Strong working knowledge of ion implantation processes and diffusion thermal tools.
• Experience with DOE methodology, statistical process control (SPC), micron-level physical inspection, and optical/electrical characterization.
• Proficiency with Python, SQL, JMP, and Excel for process monitoring and optimization.
• Strong documentation skills and experience reviewing P&IDs, leading change order processes, writing SOPs, process specs, and engineering reports.
• Ability to support a fab environment, including occasional travel to the Wilmer, TX G2 facility as needed.
• The T1 Way
• We move fast, expect accountability, and treat people with respect. We also have a no-jerks policy: we don't tolerate big egos, bad behavior or "that's not my job attitude". Be sharp, be honest, be human. If you can hold the line and have a sense of humor, you'll fit right in.
• T1 Energy is an Equal Opportunity Employer. We are committed to creating an inclusive environment for all employees and applicants and do not discriminate on the basis of any legally protected characteristics.