Bertrand Tremolet de Villers is a principal researcher in Process Science and Engineering Group within the Materials, Chemical, and Computational Science Directorate. He has physics and spectroscopy expertise in organic and hybrid-organic photovoltaic and energy storage systems, i.e., Li-ion batteries, and the scale up of these technologies. He has developed in-situ spectroscopic methods to study solid-electrolyte interfaces and electrolyte solvation structure in silicon anodes and next-gen high-nickel/low-cobalt cathodes for rechargeable cells. He has also implemented high-throughput ultrafast laser patterning for monolithic interconnects of thin-film photovoltaic modules and for rechargeable ion battery electrodes for enhanced performance.

Research Interests

Energy Storage

Thin-film Organic and Hybrid Photovoltaics

High-Throughput Ultrafast Laser Processing


Ph.D., Physical Chemistry, University of California, Los Angeles

B.S., Materials Chemistry, University of California, Los Angeles

Professional Experience

Postdoctoral Researcher, National Center for Photovoltaics, National Renewable Energy Laboratory (2013–2016)

Postdoctoral Researcher, Materials Department, University of California, Santa Barbara (2011–2013)

Featured Work

Laser ablation of Li-ion electrodes for fast charging: Material properties, rate capability, Li plating, and wetting, Journal of Power Sources (2022)

In Situ ATR‐FTIR Study of the Cathode–Electrolyte Interphase: Electrolyte Solution Structure, Transition Metal Redox, and Surface Layer Evolution, Batteries & Supercaps (2021)

Extracellular electron transfer across bio-nano interfaces for CO2 electroreduction, Nanoscale (2021)

Probing the Evolution of Surface Chemistry at the Silicon–Electrolyte Interphase via In Situ Surface-Enhanced Raman Spectroscopy, The Journal of Physical Chemistry Letters (2020)

Highly Efficient Perovskite Solar Modules by Scalable Fabrication and Interconnection Optimization, ACS Energy Letters (2018)

Tailored interfaces of unencapsulated perovskite solar cells for >1,000 hour operational stability, Nature Energy (2018)

Removal of Residual Diiodooctane Improves Photostability of High-Performance Organic Solar Cell Polymers, Chemistry of Materials (2016)

View all NREL publications for Bertrand J. Tremolet de Villers.


Laser Ablation for Lithium-Ion Batteries, U.S. Patent Application No. 63/149,466 (Filed 2021)

Sensor-Guided Adaptive Laser Ablation of Battery Electrodes, U.S. Patent Application No. 63/284,144 (Filed 2021)

Casing for Pouch Cell Batteries, U.S. Patent Application No. 63/182,107 (Filed 2021)