Microstructural, magnetotransport, and electronic subband studies of InAsxP1−x/InP modulation-doped strained single quantum wells Original Research Article

The microsturctural properties in lattice-mismatched InAs0.3P0.7/InP modulation-doped single quantum wells were investigated by using transmission electron microscopy (TEM) and the Raman scattering spectroscopy measurements, and the low-temperature magnetotransport properties of the two-dimensional electron gas (2DEG) in the InAs0.3P0.7 wells were studied using Shubnikov–de Haas (S–dH) and Van der Pauw Hall-effect measurements. The TEM measurement on the InAs0.3P0.7/InP single quantum wells showed that the InAs0.3P0.7 active layer was grown pseudomorphologically on the InP buffer layer in spite of the lattice mismatch. The values of the horizontal, the vertical strains and the horizontal stress of the InAs0.3P0.7 layer were −9.6×103, 1.07×10−2, and respectively. A possible crystal structure for the InAs0.3P0.7/InP single quantum well is presented on the basis of the TEM results. The S–dH measurements and the fast Fourier transformation results for the S–dH data clearly indicate electron occupation of one subband in the InAs0.3P0.7/InP single quantum well. The carrier density and the effective mass of the 2DEG as determined from the S–dH measurements were and 0.06256m0, respectively. The electronic structures in the quantum wells were calculated by using a self-consistent method. These present results can help improve the understanding of potential applications of modulation-doped InAsxP1−x/InP strained single quantum wells in high speed electronic devices.