Semiconductor equipment supplier, Novellus Systems, is developing what it describes as conformal film deposition (CFD) technology; an atomic layer deposition process to grow conformal metal oxide and metal nitride dipole layers in the PV cells. Collaboration is being undertaken with the University of South Florida (USF), to study the precise engineering of solar cell interfaces via a National Science Foundation (NSF) grant.
Novellus's CFD films are deposited using a new version of its ‘VECTOR’ PECVD (plasma enhanced chemical vapor deposition) system, used extensively in semiconductor manufacturing.
“The global focus and investment in emerging green technologies has necessitated the need for new fabrication techniques to make these alternative energy sources commercially viable,” noted Sesha Varadarajan, senior vice president of Novellus's PECVD business unit. “We believe, as do our partners at the University of South Florida, that conformal film deposition will be critical in building more efficient photovoltaic solar cells. As a company, this grant typifies our commitment to work with leading universities to come up with commercial solutions with a strong basis in science.”
Novellus said that growing conformal metal oxide and metal nitride dipole layers several atoms thick could enable band alignment for optimized charge transfer or blocking that enable improved photocurrent and voltage control within the cell.
Conventional ALD processes are inherently slow and not conducive to high-volume, low-cost PV manufacturing. Several companies are developing faster ALD techniques though this is the first time a major semiconductor equipment supplier is also developing the technology.
Novellus is well known for high productivity tools within the semiconductor industry. Interestingly, soon after rival, Applied Materials entered the PV equipment market, Rick Hill, Novellus’s CEO squashed all talk of the company ever following Applied into the PV sector.