Photoreflectance investigations of HEMT structures grown by MBE

Determination of surface electric potential by photoreflectance spectroscopy of HEMT heterostructures

“…On the other hand, photoreflectance spectroscopy (PR) is a technique that has been widely used for the study and characterization of semiconductor devices structures [5][6][7][8][9]. Some reports have been focused to determine the origin of Franz-Keldysh oscillations (FKO) that are usually observed in the PR spectra.…”

“…Some reports have been focused to determine the origin of Franz-Keldysh oscillations (FKO) that are usually observed in the PR spectra. Now we know that wide-period FKO above energy gap of GaAs are associated to surface electric fields and short-period FKO are originated by the internal AlGaAs/GaAs interface [8][9][10].…”

Effect of the Surface on Optical properties of AlGaAs/GaAs heterostructures with double 2-DEG

“…All PR spectra have very similar line shape despite that the samples have different thickness layers. In previous works, BP-FKO has been associated to the surface electric field [9][10][11]. By FKO analysis similar to those described elsewhere [12] we calculated the electric field strength (F S ), which range from 2.27 to 2.57 x 10 7 V/m (see table 2).…”

“…Optical approaches like photoreflectance and photoluminescence spectroscopy are very useful techniques that have been widely used for the study and characterization of AlGaAs/GaAs system [5][6][7][8][9][10][11]. Some reports have been focused to determinate the origin of FranzKeldyshoscillations (FKO) that usually are observed at the PR spectra, now we know that wideperiod FKO are associated to surface electric field and short-period FKO are originated by 299 A58 internal AlGaAs/GaAs interfaces [9][10][11].…”

“…Some reports have been focused to determinate the origin of FranzKeldyshoscillations (FKO) that usually are observed at the PR spectra, now we know that wideperiod FKO are associated to surface electric field and short-period FKO are originated by 299 A58 internal AlGaAs/GaAs interfaces [9][10][11]. In this work, we studied a set of heterostructures by PR and PL measurements in order to determinate the effects of the surface electric fieldover the conduction band behavior.…”