Electronic Raman Scattering in Photoexcited Quantum Wells: Field Effects and Charge-Density Domains
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Raman scattering has been shown to be a powerful tool for the study of the electronic properties of space-charge layers and quantum-well structures (QWS), particularly those based on the GaAs-Alx Ga1−x As system.1,2 In this work, the focus is on photoexcited QWS.3−7 Compared with modulation doping, photogenerated electron-hole systems present the disadvantages of the non-uniformity of the plasma and the non-equilibrium nature of the photoexcitation process. Advantages include the ease of the tuning of the carrier density and plasma neutrality. In particular, band discontinuities can be easily inferred from Raman measurements of intersubband separations in photoexcited QWS.4,5 This is unlike modulation-doped samples where the intersubband energies strongly depend on the (poorly-known) electrostatic potential due to the charge transfer.
KeywordsCarrier Density Scattered Photon Intersubband Transition Depolarization Shift Raman Tensor
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