Modulation Doping

Bandgap energy versus lattice constant for various elemental and compound semiconductors. The lines connecting the different compounds indicate the range of energy gaps that can be obtained by alloying the different components with similar lattice constants. 

Two different semiconductor materials with different energy gaps before forming a junction (left). The differences between the two conduction bands and between the two valence bands relative to the vacuum energy must be preserved at the junction. This condition causes discontinuities in the bands when a junction is formed and the Fermi levels are matched (right). 

Heterojunction between heavily n-doped AIGclAs and lightly n-doped GaAs. The higher concentration of electrons in the AlGaAs causes them to diffuse across the junction into the nearly intrinsic GclAs where they congregate in the well between the conduction band and the Fermi level. 

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MODFET. See Modulation doped field-effect transistor. 

Modified starch Modified starches Modifiers Modularity Modulation contrast Modulation doped FETs Module designs Mogadon... 

H. Morkoc and H. Vnlu, Factors Affecting the Performance of (Al, Ga)As/GaAs and (Al, Ga)As/InGaAs Modulation-Doped Field-Effect Transistors Microwave and Digital Applications... 

Al, Ga)As/InGaAs Modulation-Doped Field-Effect Transistors Microwave and Digital Applications... 

In order to solve the problems of the low solubility of magnetic ions in III-V semiconductors and the difficulty of the carrier control in II-VI semiconductors, modulation-doped III-V/II-VI superlattice structures have been proposed (Kamatani and Akai 2001a). Here, a... 

As mentioned in the preceding section the mobility of degenerately-doped zinc oxide (as well as of other TCO materials and semiconductors) is limited by ionized impurity scattering in homogeneously-doped materials. Since about 30 years it is well known that the mobility can be increased by the so-called modulation doping method, introduced by Dingle et al. [179] for GaAs/C.ai, Af As superlattice structures (for a review see [180]). 

Fig. 2.18. Kelvin probe force microscopy (KPFM) picture of the cross-section of a modulation doped Zni- Mg CtAl/ZnO film on a silicon substrate. The contact potential is given relative to pyrolytic graphite ( = 4.07 eV). The local variation of the contact potential is shown on the left side, while the chemical composition, determined by SIMS is displayed on the right side. Deposition parameters p = 0.2Pa, P = 75Wrf, Tsub = 300°C, single layer thickness dZno = dZni xMgxO Ai = 160 nm...

MBE MD-SLS MESFET molecular beam epitaxy modulation doped strained-layer superlattice metal-semiconductor field effect transistor... 

P PAE PD PDS PEC PL PLE PMBE PPC PPPW PR PV PWP PWPP pi-MODFET precipitate power added efficiency photodetector photothermal deflection spectroscopy photoelectrochemical photoluminescence photoluminescence excitation spectroscopy plasma-assisted molecular beam epitaxy persistent photoconductivity pseudo-potential plane-wave photoreflectance photovoltage plane-wave pseudo-potential plane-wave pseudo-potential piezoelectric modulation doped field effect transistor... 

Dingle, R. Stormer, H.L. Gossard, A.C. Wiegmann, W. Electron mobilities in modulation-doped semiconductor heterojunction superlattices. Appl. Phys. Lett. 1978, 33, 665. 

D. Reznik and E. Scholl Oscillation modes, transient chaos and its control in a modulation-doped semiconductor double-deterostructure, Z. Phys. B 91, 309 (1993). 

High Electron Mobility Transistors (Modulation Doped Field Effect Transistors [HEMTs (MODFETs)]... 

A field-effect transistor has been prepared using a modulation doped GaAs/InQ 2GaQegAs SLS as the channel of the device (35). The device consisted of a p-type GaAs substrate, a p-type (4 x 10- 8 cm J), 1 pm InQ.jGaQ.gAs bufffer, an n-type (1 x 101 cm J),... 

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