Fano-type Effect in Hydrogen-Terminated Pure Nanodiamond
Oleg S. Kudryavtsev, R. Kh. Bagramov, A. M. Satanin, A. A. Shiryaev, Oleg I. Lebedev, Alexey M. Romshin, Dmitrii G. Pasternak, А. В. Николаев, В. П. Филоненко, И. И. Власов
Abstract
Two novel properties, unique for semiconductors, a negative electron affinity and a high p-type surface electrical conductivity, were discovered in diamond at the end of the last century. Both properties appear when the diamond surface is hydrogenated. A natural question arises: is the influence of the surface hydrogen on diamond limited only to the electrical properties? Here, for the first time to our knowledge, we observe a transparency peak at 1328 cm–1 in the infrared absorption of hydrogen-terminated pure (undoped) nanodiamonds. This new optical property is ascribed to Fano-type destructive interference between zone-center optical phonons and free carriers (holes) appearing in the near-surface layer of hydrogenated nanodiamond. This work opens the way to explore the physics of electron–phonon coupling in undoped semiconductors and promises the application of H-terminated nanodiamonds as a new optical material with induced transparency in the infrared optical range.