User:John R. Brews

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I am a Professor Emeritus of Electrical Engineering from The University of Arizona, where I taught device physics and circuit design for just under two decades. Previously, I was a research scientist for twenty-odd years at Bell Laboratories, Murray Hill, doing theoretical work in the areas of solid-state physics and device physics. I also am a Fellow of the IEEE, and a recipient of the Electron Device Society distinguished service award for work as Editor-in-chief of the journal IEEE Electron Device Letters, founded by Nobel prize winner George E. Smith. I've published a number of technical books and papers, some of which may be found at this link.


Images

Magnetism
B-field lines near uniformly magnetized sphere
(CC) Image: John R. Brews
B-field lines near uniformly magnetized sphere
Magnetic flux density vs. magnetic field in steel and iron
(CC) Image: John R. Brews
Magnetic flux density vs. magnetic field in steel and iron
Widlar current source
Widlar current source using bipolar transistors
(CC) Image: John R. Brews
Widlar current source using bipolar transistors
Small-signal circuit for finding output resistance of the Widlar source
(CC) Image: John R. Brews
Small-signal circuit for finding output resistance of the Widlar source
Design trade-off between output resistance and output current in Widlar source
(CC) Image: John R. Brews
Design trade-off between output resistance and output current in Widlar source
Forces
Force and its equivalent force and couple
(CC) Image: John R. Brews
Force and its equivalent force and couple
Electromagnetism
Electric motor using a current loop in a magnetic flux density, labeled B
(CC) Image: John R. Brews
Electric motor using a current loop in a magnetic flux density, labeled B
Devices
Cross section of MOS capacitor showing charge layers
(PD) Image: John R. Brews
Cross section of MOS capacitor showing charge layers
Three types of MOS capacitance vs. voltage curves. VTH = threshold, VFB = flatbands 
(PD) Image: John R. Brews
Three types of MOS capacitance vs. voltage curves. VTH = threshold, VFB = flatbands 
Small-signal equivalent circuit of the MOS capacitor in inversion with a single trap level
(PD) Image: John R. Brews
Small-signal equivalent circuit of the MOS capacitor in inversion with a single trap level
A modern MOSFET
(PD) Image: John R. Brews
A modern MOSFET
A power MOSFET; source and body share a contact.
(PD) Image: John R. Brews
A power MOSFET; source and body share a contact.
Calculated density of states for crystalline silicon.
(CC) Image: John R. Brews
Calculated density of states for crystalline silicon.
Field effect: At a gate voltage above threshold a surface inversion layer of electrons forms at a semiconductor surface.
(CC) Image: John R. Brews
Field effect: At a gate voltage above threshold a surface inversion layer of electrons forms at a semiconductor surface.
Occupancy comparison between n-type, intrinsic and p-type semiconductors.
(PD) Image: John R. Brews
Occupancy comparison between n-type, intrinsic and p-type semiconductors.
Nonideal pn-diode current-voltage characteristics
(PD) Image: John R. Brews
Nonideal pn-diode current-voltage characteristics
Band-bending diagram for pn-junction diode at zero applied voltage
(PD) Image: John R. Brews
Band-bending diagram for pn-junction diode at zero applied voltage
Band-bending for pn-diode in reverse bias
(PD) Image: John R. Brews
Band-bending for pn-diode in reverse bias
Quasi-Fermi levels in reverse-biased pn-junction diode
(PD) Image: John R. Brews
Quasi-Fermi levels in reverse-biased pn-junction diode
Band-bending diagram for pn-diode in forward bias
(PD) Image: John R. Brews
Band-bending diagram for pn-diode in forward bias
Fermi occupancy function vs. energy departure from Fermi level in volts for three temperatures
(PD) Image: John R. Brews
Fermi occupancy function vs. energy departure from Fermi level in volts for three temperatures
Fermi surface in k-space for a nearly filled band in the face-centered cubic lattice
(PD) Image: John R. Brews
Fermi surface in k-space for a nearly filled band in the face-centered cubic lattice
A constant energy surface in the silicon conduction band consists of six ellipsoids.
(PD) Image: John R. Brews
A constant energy surface in the silicon conduction band consists of six ellipsoids.
Planar Schottky diode with n+-guard rings and tapered oxide.
(PD) Image: John R. Brews
Planar Schottky diode with n+-guard rings and tapered oxide.
Comparison of Schottky and pn-diode current voltage curves.
(PD) Image: John R. Brews
Comparison of Schottky and pn-diode current voltage curves.
Schottky barrier formation on p-type semiconductor. Energies are in eV.
(PD) Image: John R. Brews
Schottky barrier formation on p-type semiconductor. Energies are in eV.
Under forward bias VF the Schottky barrier height is reduced and the Fermi levels are split.
(PD) Image: John R. Brews
Under forward bias VF the Schottky barrier height is reduced and the Fermi levels are split.
Schottky diode under reverse bias VR.
(PD) Image: John R. Brews
Schottky diode under reverse bias VR.
Critical electric field for breakdown versus bandgap energy in several materials.
(PD) Image: John R. Brews
Critical electric field for breakdown versus bandgap energy in several materials.