Study on epsilon crossover wavelength tuning of heavily doped germanium on silic

In this paper, we demonstrate that n-type heavily doped germanium (Ge) can serve.as a sort of CMOS-compatible, permittivity crossover wavelength (at which the real part of.permittivity changes sign) wide range adjustable epsilon-zero material in mid-infrared (MIR)..The antimony (Sb) doped Ge films w