Materials Science and Engineering - Electronic and Mechanical Properties of Materials Part 10 pps

... Tuller-2001 For R 9 3.225 9 Equation of Motion - Impact of Collisions Assume: • probability of collision in time dt = dt/τ • time varying field F(t) v(t+dt) = ( 1- dt/τ) {v(t) +dv} = ( 1- dt/τ) ... L/Wt = ρ L/A ⇒ρ(οhm-cm) σ = 1/ρ ⇒ σ (οhm-cm) -1 ⇒σ (Siemens/cm) (Test your dimensions: σ=E/j=neµ) Ohms/square ⇒ Note, if L=W, then R= ρ /t independent of magnitude...

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... Eg=1.1eV, and let µ e and µ h be approximately equal at 100 0cm 2 /V-sec (very good Si!). σ ~10 10 cm -3 *1.602x10 -1 9 *100 0cm 2 /V-sec=1.6x10 -6 S/m, or a resistivity ρ of about 10 6 ohm-m max. ... 10 18 cm -3 donors to Si: n~N d –n ~10 18 cm -3 , p ~10 2 (n i 2 /N d ) • Can change conductivity drastically – 1 part in 10 7 impurity in a crysta...

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... temperature conductivity: σ = 4.4 10 -1 8 S cm -1 8 9 10 11 12 13 10 -7 10 -6 10 -5 10 -4 Y-cut σ 0 = 2.1 S cm -1 E A = 105 kJ mol -1 10 4 /T [1/K] σ [S cm -1 ] 900 800 700 600 500 T ... 0 0 -1 0 0 10 20 30 40 50 60 70 80 90 100 110 -1 0 0 10 20 30 40 50 60 70 80 90 100 110 MFC2 Temp NO2 NH3 Feuchte CO NO2kl H2 Pt -1 00...

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... 1,005 -1 6 -4 0 -5 -4 -3 -2 -1 0 1 donor acceptor -2 0 -1 2 -8 donor doped acceptor doped 2 3.225 15 Designer Wavelengths Variation of band-gap energy with composition x of In 1-x Ga x As. ... High Acceptor Concentration in SrTiO 3 10 -2 0 10 -1 5 10 -1 0 10 -5 10 0 0,1 1 750°C 800°C 900°C 850°C 950°C electrical conducti...

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... (xrays) can be ‘particle-like’ • DeBroglie – matter can act like it has a ‘wave-nature’ • Schrodinger, Born – Unification of wave-particle duality, Schrodinger Equation Wave-particle Duality: ... interact, i.e. absorb energy and contribute to properties T F ~10 4 K (T room ~10 2 K), E F ~100 E class , v F 2 ~100 v class 2 © E. Fitzgerald-1999 2 3.225 21 Free Part...

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... when you join these together? © E. Fitzgerald-1999 3.225 12 - - + + + + Holes diffuse Electrons diffuse + + + + - - - - + + + + - - + + + + An electric field forms due to ... 3.225 11 The p-n Junction (The Diode) • Note that dopants move the fermi energy from mid-gap towards either the valence band edge (p-type) or the conduction band edge (n-t...

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... ; 1 ' ''' + − = + − += += nn n i so r Water molecule: τ=9.5x10 -1 1 sec, ω ~10 10 microwave oven, transmission of E-M waves logωτ -2 0 +2 ε’,ε’’ n 2 ε so α e +α i α e 3.225 20 Dielectric Constant ... positions of positive and negative ions © E. Fitzgerald-1999 3.225 4 Ferroelectrics Applications • Capacitors • Non-volatile memories • Photorefractive...

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... are:) n=1,2,3,… =0,1,2,…,n-1 m l =- , - +1,…,0,…, , (m s =+ or - 1/2) l l l l 0 -1 3.6eV U(r) © E. Fitzgerald-1999 ) in -1 3.225 9 Diffraction Picture of the Origin of Band Gaps Probability Density=probability/volume ... the valence band to the conduction band E c near band gap E v near band gap E k E=hν Creates a ‘hole’ in the valence band © E. Fitzgerald-1999 3.2...

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... material Material Type χ Paramagnetic +10 -5 -1 0 -4 Diamagnetic -1 0 -8 -1 0 -5 Ferromagnetic +10 5 2 5 3.225 5 © E. Fitzgerald-1999 Microscopic Source of Magnetization • No monopoles • magnetic ... 2(atomic distance cinteratomi 2 >≡ a r r J is a function of distance! 8 3.225 8 © E. Fitzgerald-1999 Ferromagnetism M T T C () ( ) () ( ) 1. 4-1 .3 0....

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... 7.5 x 10 14 Hz) λ = c/ν = 400 nm k=2π/ λ = 1.57 x 10 7 m -1 ω = 2 πν = 4.71 x 10 15 s -1 After Livingston ε ) ε (kx- ) ε 6 3.225 23 • Scaling of Si CMOS includes conductivity engineering ... e -i(kx-ωt) are all waves e -i(kx-ωt) is the complex one and is the most general real imaginary A Acosθ iAsinθ θ e iθ =cosθ+isinθ © E.A. Fitzgerald-1999 1 3....

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