Senior Process Engineer, Wet Etch

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 is seeking a Senior Wet Etch Engineer to develop, qualify, and own the wet chemical processes used to manufacture TOPCon solar cells at scale, including texturing, cleaning, and etch steps. You’ll apply a physics-based approach to process development, partner across engineering teams, and drive cell efficiency and yield improvement as we bring a new high-volume fab online. WHAT YOU'LL DO • Develop, qualify, and own wet processes for TOPCon cell manufacturing, including saw damage removal, alkaline texturing, rear-side etch and polish, edge isolation, and pre-deposition and pre-diffusion cleans • Own bath chemistry, concentration control, temperature management, dosing, and bath life for alkaline, acidic, and oxidizing chemistries, including HF, KOH/NaOH, and ozone-based steps • Optimize BSG, PSG, and polysilicon wrap-around removal, texture quality, reflectance, and surface cleanliness to improve cell efficiency, minority carrier lifetime, and passivation performance • Qualify inline and batch wet process tools from installation through production readiness, partnering with Equipment, Metrology, and Quality on process matching, particle and metal contamination control, and wafer breakage reduction • Lead root cause analysis for yield excursions and efficiency losses using a first-principles, physics-based approach, and establish inline metrology and control strategies to drive systematic improvement • Support 24/7 manufacturing operations through rotations, on-call availability, and rapid response to critical production issues • Drive next-generation wet chemistry formulations, additives, and process development to reduce cost and improve cell performance WHO YOU ARE • A wet process practitioner — you know wet etch and wet clean well and have hands-on development and manufacturing experience to back it up • A first-principles thinker who looks for the mechanism behind a result, not just the recipe that produced it • Rigorous and data-driven, with strong Design of Experiments and statistical analysis skills • Collaborative and proactive across process, equipment, metrology, quality, and R&D teams • Energized by the challenge of scaling advanced cell technology in a new fab environment QUALIFICATIONS • Degree in Chemical Engineering, Materials Science, Electrical Engineering, Physics, or a related technical field, or equivalent experience • 5+ years of hands-on wet process engineering experience in solar cell or semiconductor manufacturing, with a strong preference for TOPCon or other high-efficiency cell technologies • Deep experience with wet process development, tool qualification, and establishing process baselines and control plans in high-volume manufacturing • Working knowledge of texturing, cleaning, and etch chemistries and their impact on surface passivation, lifetime, and cell efficiency • Proficiency with wet process metrology, including reflectance, film thickness, particle and defect inspection, lifetime measurement, and surface analysis techniques • Strong Design of Experiments skills and statistical analysis capability • Experience handling hazardous chemicals safely 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.