Superlattices doping

Fig. 10.14 TEM cross-sectional micrograph of a one-dimensional porosity superlattice. Anodization was performed on a periodically p-doped substrate (75 nm of 1017 citT3, 75 nm of 1019 crrT3) using a current density of... 

H. Morkoc, F. Hamdani, and A. Salvador, Electronic and Optical Properties of IIT-V Nitride based Quantum Wells and Superlattices K. Doverspike and J. /. Pankove, Doping in the 111-Nitrides... 

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... 

The partial density of states (DOS) of the n-th subband gives a step-like increase of the total DOS when the chemical potential reaches the bottom of the subband n=l,2,3 where a type (I) ETT occurs as shown in Fig. 5. The DOS peaks in Fig. 5 are due to partial DOS of each subband tuning the chemical potential by electron doping at the vHs associated with the type (III) ETT in each subband. The panel (b) of Fig. 5 shows the details of the DOS near the type (III) ETT at Ec in the third subband as a function of the reduced Liftshitz parameter " z"—(EF —Ec)/W where W is the dispersion of the third subband in the y direction of the superlattice, transversal to the nanotube direction. 

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]). 

A high-quality GalnN/GaN MQW heterostructure was successfully fabricated by MOVPE. The fine superlattice structure was directly detected using TEM and SIMS analysis. The MQW greatly enhanced the optical efficiency in non-doped MQWs compared with the bulk GalnN layer. Consequently, the GalnN/GaN MQW is promising for die active layers of LEDs and LDs. 

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

Volume 24 Applications of Multiquantum Wells, Selective Doping, and Superlattices... 

Fig. 9.31. Dlustration of the potential modulation of the bands of a doping superlattice. The dashed line illustrates the screening of the potential by photoexcited charge carriers. Recombination of electrons and holes is by tunneling between layers.

Even more curious phenomena occur in doping superlattices which are cooled from elevated temperature with an applied bias (Fritzsche, Yang and Takada 1988). Fig. 9.33 shows that the material is non-... 

The more traditional approach has already been used in anodic electrocrystallization processes to produce nanocompositions and superlattices of mixed Ti-Pb oxides [341-347]. With HTSC materials, initial steps have been made in this direction in studies on the electrochemical deposition of conductive polymers on the surface of microband YBCO electrodes [28,50,433]. In the resulting composition, the reversible transition from the HTSC/metal junction (at the high doping degree of the polymer) to the HTSC/semiconductor junction has been achieved. The properties of these compositions allow one to control the shift over a wide interval. 

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

Dingle R. (1987), Semiconductors and Semimetals Applications of Multiquantum Wells, Selective Doping, and Superlattices, Vol. 24, Academic Press, New York. 

J. Kastrup, R. Klann, H. T. Grahn, K. Ploog, L. L. Bonilla, J. Galan, M. Kindelan, M. Moscoso, and R. Merlin Self-oscillations of domains in doped GaAs-AlAs superlattices, Phys. Rev. B 52, 13761 (1995). 

EFFECTS OF DOPING AND NONRADIATIVE DEFECTS IN GaAs SUPERLATTICES... 

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