Mechanics of nanostructures and semiconductor quantum heterostructures.

(1) QD induced strain field

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Figure 1. Contours of hydrostatic strain gkk (10-3) on the traction-free and isolating surface of a substrate due to a point QD at a depth h=10nm below the surface. Isotropic GaAs substrate in (a), substrate GaAs (001) in (b), and substrate GaAs (111) in (c) (See Pan, E. (2002): Elastic and piezoelectric fields in substrates GaAs (001) and GaAs (111) due to a buried quantum dot. Journal of Applied Physics 91: 6379-6387.)

 

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Figure 2. Piezoelectric potential in the (-110) plane induced by (a) spherical, (b) cubic, and (c) pyramidal dots containing the same volume of InAs in GaAs. The potential goes from 0 (white) to ±+0+0+00.16V (positive in red and negative in blue). (Courtesy of Davies, 1998).

 

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Figure 3. Contouof horizontal electric field Ex (X107 V/m) on thfree surface of substrate AlN (1000) in (a) and AlN (0001) in (b) due to a QD at a depth h=10nm. (See Pan, E. and Yang, B. (2003): Elastic and piezoelectric fields in a substrate AlN due to a buried quantum dot. Journal of Applied Physics 93: 2435-2439.)

 

 

(2) Full- vs. Semi-Coupled Model (See Pan, E. (2002): Elastic and piezoelectric fields around a quantum dot: Fully coupled or semi-coupled model.Journal of Applied Physics 91: 3785-3796.)

 

I. Elastic Strain Field

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II. Electric Field

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(3) Piezoelectric Potential in GaAs (001) and (111) (See Pan, E. (2002): Elastic and piezoelectric fields in substrates GaAs (001) andGaAs (111) due to a buried quantum dot. Journal of Applied Physics 91: 6379-6387.)

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Contours of vertical electric field on the surface of isotropic crystal 001 Contours of the electric potentialon the surface of GaAs (111) due to a point quantum dot of volume va applied at distance h=10 nm.due to a point quantum dot of volume va applied at distance h=10 nm.

 

 

(4) Vertical Electric Field in GaAs (See Pan, E. (2002): Elastic and piezoelectric fields in substrates GaAs (001) and GaAs (111) due to a buried quantum dot. Journal of Applied Physics 91: 6379-6387.)

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Contours of vertical electric field on the surface of GaAs 001 Contours of vertical electric field Ez on the surface of GaAs 111 due to a point quantum dot of volume va applied at distance h=10 nm. due to a point quantum dot of volume va applied at distance h=10 nm.

 

 

(4) Elastic and Electric fields induced by QWR