Working with thermionic emission to determine the current from a platinum wire.
Find the value of the thermionic current in Amp/cm2 for a platinum filament whose work function is 4.1 eV and temperature is 2000 K. The emission constant A is 120 A/(cm2 K2).
Copper has a breaking stress of 3 x 10^8 N/m2. (a) What is the maximum load that can be hung from a copper wire of diameter of 0.42 mm before it breaks? (b) If half this maximum load is hung from the wire, by what percentage of its length will it stretch ?
quasi Fermi levels,conductivity
An undoped Si sample is optically excited at 300K such that Gop=10^19 ehp/cm^3s and taun=taup=1 microseconds. (a) What is the separation of the quasi Fermi levels (Efn-Efp)? (b) Where is Efn and Efp with respect to the intrinsic Fermi level Ei? (c) What is the change in conductivity due to excess carriers? What are the a ...continues
Designing a fun and happy resistor
An n-type Si resistor is to be designed so that it carries a current of 5mA with an applied voltage of 5V. T=300K. Mn*=.26M0. M0=9.11x10^31Kg. (a) If Nd=10^15/cm^3 and Na=0, design a resistor to meet the required specifications. (b) If Nd=3x10^16/cm^3 and Na=2.5x10^16/cm^3, redesign the resistor. What are the answers and ...continues
Consider a gold Schottkey diode at T=300k formed on a n-type GaAs doped at Nd=5x10^16 cm^-3. Among other things find Phi|n. Phi|n=KT/e*ln(Nc/Nd) I don't understand how to get Nc from the information given here. What is NC given the information stated in the problem? Thanks.
Consider an ideal pn junction diode at T=300K operating in the forwared bias region. Calculate the change in diode voltage that will cause a factor of 10 increase in current. I was trying to use the ideal diode current equation, but I don't know how to find Is from the given information. How do I work this problem?
A schottky diode and a pn junction diode have cross sectional areas a=10^-4. The reverse saturation current density of the pn junction diode is 3x10^-8 A/cm^2. The reverse saturation current density of the pn junction diode is 3x10^-12A/cm^2. Determine the forward bias voltage in each diode required to yeild diode currents o ...continues
An example says, Na=10^18cm^-3 Nd=10^16cm^-3 Dp=10cm^2/s Dn=25cm^2/s tpo=10^-7s tno=10^-7s "We can then calculate the following parameters:" Lp=1.0x10^-3cm Ln=1.58X10^-3cm pno=2.25x10^4cm^-3 npo=2.25x10^2cm^-3 How were the lengths and minority carrier concentrations derived from the above information? and math ...continues
Consider n-type silicon in an MOS structure. Let T=300K. Determine semiconductor doping so that |Q'sd(max)|=7.5x10^-9C/cm^2. Determine the surface potential that results int he maximum space charge width.
Consider an aluminum gate-silicon dioxide p type silicon MOS structure with tox=450 angstroms. The silicon doping is Na=2x10^11cm^-3 and the flat-band voltage is Vfb=-1.0V. Determine the fixed oxide charge Q'ss.
