TY - JOUR
T1 - Electric fields separation by phase selection in modulation spectroscopy of photoreflectance
AU - Wang, Y. C.
AU - Chou, W. Y.
AU - Hwang, W. C.
AU - Hwang, J. S.
N1 - Funding Information:
Acknowledgements-This work was supported by National Science Council of the Republic of China under Contract No. NCS 85-2112-M-006-008.
PY - 1997/12
Y1 - 1997/12
N2 - The built-in electric fields in a MBE grown δ-doped GaAs homojunction have been investigated by the techniques of photoreflectance and phase suppression. Two Franz-Keldysh oscillation features originating from two different fields in the structure superimpose with each other in the photoreflectance spectrum. By properly selecting the reference phase of the lock-in amplifier, one of the features can be suppressed, thus enabling us to determine the electric fields from two different regions. We have demonstrated that only two PR spectra, in-phase and out-phase components, are needed to find the phase angle which suppresses one of the features. The electric field in the top layer is 3.5 ± 0.2 × 105 V cm-1, which is in good agreement with theoretical calculation. The electric field in the buffer layer is 1.2 ± 0.1 × 104 V cm-1, which suggests the existence of interface states at the buffer/substrate interface.
AB - The built-in electric fields in a MBE grown δ-doped GaAs homojunction have been investigated by the techniques of photoreflectance and phase suppression. Two Franz-Keldysh oscillation features originating from two different fields in the structure superimpose with each other in the photoreflectance spectrum. By properly selecting the reference phase of the lock-in amplifier, one of the features can be suppressed, thus enabling us to determine the electric fields from two different regions. We have demonstrated that only two PR spectra, in-phase and out-phase components, are needed to find the phase angle which suppresses one of the features. The electric field in the top layer is 3.5 ± 0.2 × 105 V cm-1, which is in good agreement with theoretical calculation. The electric field in the buffer layer is 1.2 ± 0.1 × 104 V cm-1, which suggests the existence of interface states at the buffer/substrate interface.
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U2 - 10.1016/S0038-1098(97)00205-6
DO - 10.1016/S0038-1098(97)00205-6
M3 - Article
AN - SCOPUS:0031378174
SN - 0038-1098
VL - 104
SP - 717
EP - 721
JO - Solid State Communications
JF - Solid State Communications
IS - 12
ER -