Stoichiometry Control and Doping of II-VI Semiconductors

For II-VI materials and device applications, it is critical to be able to influence both the concentration and lifetime of charge carriers within the material that allow conduction to occur. For example, the inability to increase the carrier concentration in standard polycrystalline CdTe beyond 10¹⁵ cm^-3 limits solar cell efficiency. Adjusting the stoichiometry of CdTe materials to create material that is more Cd-rich or Te-rich can improve carrier lifetime, but limits the incorporation of dopants that can increase carrier concentration. New technology is needed that enables both a longer carrier lifetime as well as a higher carrier concentration in order for CdTe devices to continue to improve.

from Energy Innovation Portal Technology Ticker https://techportal.eere.energy.gov/technology.do/techID=1579