Optical Properties ofn-Type InP

Measurements of the intrinsic absorption edge of $n$-type InP at 77°K and 300°K are reported. Differences are found in the spectra of samples of differing origin. The effects are believed due to impurities. Reflection and absorption spectra in the vicinity of the reststrahlen peak are shown. The reststrahlen wavelength is 30.5 μ, the static and high-frequency dielectric constants are ${\epsilon }_0=15\mathrm{}$ and ${\epsilon }_{\infty }=10.6\mathrm{}$. Freecarrier absorption and reflection spectra are shown. A brief discussion of the implications of the various optical and electrical measurements as regards the conduction band structure is given.