Photovoltaic effects on Franz–Keldysh oscillations in photoreflectance spectra: Application to determination of surface Fermi level and surface recombination velocity in undoped GaAs∕n-type GaAs epitaxial layer structures

Abstract

Photovoltaic effects on Franz-Keldysh oscillations in photoreflectance spectra: Application to determination of surface Fermi level and surface recombination velocity in undoped GaAs∕n-type GaAs epitaxial layer structures.

Determination of surface electric potential by photoreflectance spectroscopy of HEMT heterostructures

“…This result can be accounted for in terms of the thermal distribution of electrons. Based on the Boltzmann statistics, the relationship between the surface potential f S and electron density N S at the surface can be written as [12] f s ¼ KT In…”

Observation and quantification of the direction reversal of the surface band bending in GaAs1‐xNx using terahertz electromagnetic wave and photoreflectance measurements

“…In addition, the i-GaAs(200 nm)/n-GaAs(3 μm, 3×10 18 cm -3 ) epitaxial layer structure was a used as a reference sample in the THz wave measurement, where the values in the parentheses denote the individual layer thickness and doping concentration. The potential structure of the i-GaAs/nGaAs sample has already been investigated [5,6]. The conduction-band energy has a finite potential slope in the iGaAs layer induced by the surface Fermi-level pinning, which produces a uniform built-in electric field of 35 kV/cm in the i-GaAs layer.…”

Frequency-tunable terahertz electromagnetic wave emitters based on undoped GaAs/n-type GaAs epitaxial layer structures utilizing sub-picosecond-range carrier-transport processes

“…The parameters used in the calculations are the same as those used in Ref. [5]. It should be noted that the surface Fermi level of i-GaAs is located almost at the center of the band gap [5,6].…”