Practice4 - ME 083 Spring 2002 Structure and Properties of...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
ME 083 Spring 2002 Structure and Properties of Solids Practice Exam #4 April 24, 2002 Problem 1: Semiconductors (a) Sketched below is a p-n junction diode in two diferent circuits: p n - + (a) p n + - (b) Figure 1: p-n junction diaode. Which o± these two circuits will conduct electricity? Why? O± what engineering use is such a diode? 1
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
- m ) - 1 at 10 o C and 172 (Ω - m ) - 1 at 17 o C . What is the band gap of this semiconductor? (c) Suppose a piece of silicon is doped with phosphorous in a concentration of 10 26 m - 3 . The intrinsic carrier concentration of silicon at room temperature is 2 × 10 16 m - 3 . Calculate the resulting hole concentration at room temperature. (c) GaAs (gallium arsenide) is a semiconducting material which can be made to convert elec- tricity to light with a very high eFciency. Actually, it is a semiconducting laser. Sketch the band structure you would expect for GaAs assuming it is an intrinsic semiconductor. Label all pertinent features.
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/19/2010 for the course MECH ENG 083 taught by Professor Zauscher during the Spring '04 term at Duke.

Page1 / 5

Practice4 - ME 083 Spring 2002 Structure and Properties of...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online