Bill McMahon has conducted research at NREL for more than 25 years. During this time, he has performed foundational research on a wide range of topics impacting the growth, fabrication, and performance of high-efficiency III‑V solar cells. As a postdoctoral researcher, he studied the atomic structure of MOCVD-prepared semiconductor surfaces used in III‑V growth on silicon and germanium surfaces. His research into the atomic structure of dislocations explained how ordering of III-V alloys can increase the glide force on dislocations, impacting the growth of lattice-mismatched solar cells. He has also led investigations into cell bonding, nano-imprinted optical coatings, distributed resistance modeling of 3-D current flow in multijunction solar cells, and energy-yield measurement and modeling.
Research Description
Developing foundational knowledge for the design, characterization and measurement of three-terminal solar cells and voltage-matched strings
Using a fundamental understanding of dislocation formation in coalescing materials to direct projects investigating III-V growth on inexpensive and reusable substrates