Browsing by Author "Lou, Shry-Fong"

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Electrooptical Properties of InGaAs/GaAs Strained Single Quantum Wells
(2000)
Lu, Chien-Rong
;
Lou, Shry-Fong
;
Cheng, Hung-Hsiang
;
Lee, Chien-Ping
;
Tsai, Fu-Yi
The electrooptical properties of (100) and (111)B InGaAs/GaAs strained single quantum wells have been studied by the photoreflectance spectroscopy at various temperatures and under different biases. There is a Si delta-doping sheet under the GaAs surface to screen the surface built-in electric field from the quantum well. The spectral features consist of the excitonic interband transitions in the quantum well, and the Franz-Keldysh oscillations from the band edge transitions of the GaAs barrier near the surface. The piezoelectric field tilts the (111)B single quantum well toward the Si delta-doping and causes subband filling by the electrons from the delta-doping centers. With a proper external bias to repel electrons from the tilted quantum well, the excitonic interband transition in the (111)B system is enhanced.