Comment on “A model for internal photoemission at high-k oxide/silicon energy barriers” [J. Appl. Phys. 112, 064115 (2012)]

Abstract

The conclusions of the recently proposed model for internal photoemission of electrons at the interfaces between silicon and high-k oxides [O. Engström, J. Appl. Phys. 112, 064115 (2012)] have been compared to some of the available experimental results. In this Comment, it is shown that this model cannot fully account for a number of significant observations and, therefore, is limited in its use for analysis of internal photoemission spectra.

Energy Band Alignment of a Monolayer MoS2 with SiO2 and Al2O3 Insulators from Internal Photoemission

“…Once filled by electrons from Si electrode, optical excitation of these defects can be responsible for photocurrent “tails” stretching down to , cf., e.g., Figure a in ref. . Due to the contribution of the defect‐related signal and the distortion of the spectra by the optical feature at , the spectral range over which Equation can be used for the IPE spectral threshold determination appears to be rather limited as evident from Figure b.…”

Band offsets and trap-related electron transitions at interfaces of (100)InAs with atomic-layer deposited Al2O3

“…Rather, the featureless spectral curves in the range h ¼ 2.0-3.5 eV resemble the signals related to the excitation of electron states inside the IL between InAs and the oxide on top. 38 Therefore, the yield spectra shown in Fig. 1 apparently contain contributions stemming from at least two different photocurrent generation mechanisms.…”

Conduction-band tail states of thermally grown GeO<inf>2</inf> on Ge detected by internal photoemission spectroscopy

“…5 Finally, the optical absorption inside Ge is discussed from a possible influence on the IPE spectral yield shape. [6][7][8] In case of Ge, however, the energy band structure consideration supports that it is not necessary to take account of those effects, and that the IPE spectral shift is derived from GeO 2 characteristics.…”