Assume that the mobility of electronics in silicon at T=300K is MUn=1300cm^2/V-s. Also assume that the mobility is limited by latice scattering and varies as T^-(3/2). Determine electron mobility at (a) T=200K and (b) T=400K. (There are numerous graphs in the book and no formulas that I could find to help solve this probl ...continues
I'm having trouble getting the answer the back of the book does after trying to calculate the quasi fermi level. The book gets Efn-Efi=.3498eV; Efi-Efp=.2877eV Q. An n-type silicon sample with Nd=10^16cm-3 is steadily illuminated such that g'=10^21cm-s^-1. If tn0=tp0=10^-6s, calculate the position of the quasi-Fermi leve ...continues
Excess carrier concentrations and diffusion current density
Consider a bar of p-Si that is homogeneously doped to a value of 3x10^15 at T=300K. The applied electric field is zero. A light source is incident on the end of the semiconductor. The excess-carrier concentration generated at x=0 is deltap(0)=deltan(0)=10^13/cm^3. Neglect surface effects. Mun=1200/cm^2/Vs. Mup=400/cm^2/V ...continues
Consider the 2.0micrometer long GaAs device where the E-field is 5kV/cm and Mn*=.067M0. (a) Calculate the transit time of an electron through the device if the mobility is 8000 cm^2V-s. (b) The mean free path of an electron (average velocity x scattering time) is the average distance an electron travels between two consecu ...continues
Two thin-walled circular tubes, one having a seamless section, the other a split section(see attachment), are subjected to the action of identical twisting moments. Both tubes have equal outer diameter "Do", inner diameter "Di", and thickness "t". Determine the ration of their angles of twist.
Two bars, one having a circular section of radius b, the other an elliptic section with semiaxes a,b. For equal angles of twist, which bar experiences the larger shearing stress? For equal allowable shearing stresses, which one resists a larger twisting moment?
Calculate reactions of a simply supported continuous beam.
A beam is simply supported at the ends and is continuous over two spans. The left-hand span is 16 ft. and the right-hand span is 20 ft. The beam supports a uniform load of 900 plf, which includes its own weight, over the entire 36 ft. span and also a concetrated load of 8000 lb applied at a point that is 5 ft. from the l ...continues
Determine the reactions of simply supported beam to both a concentrated and uniform load.
A beam with a span of 21 ft is simply supported at the left-hand end and fixed at the right-hand end. It carries a uniform load of 800 plf, which includes its own weight, over its entire span and a concentrated load of 12,000 lb located 7 ft from the left-hand end. The total bending moment at the fixed end is equal to -81,4 ...continues
Calculate bending moments, radius of gyration, axial loads, etc.
Please see the attached files for full problem descriptions.
Q1: Explain clearly the fabrication steps involved in the fabrication of Organic LED. (a full page) Q2: Compare the brightness of OLED quantitatively with semiconductor LED emitting in red, green and blue colors. (half a page)
