Ece340Fall03HW5sol - ECE 340 Homework V Fall 2003 Due Wednesday Solution 30 points total 1 An p-type Si sample with N a = 2x10 16/cm 3 is steadily

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon

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

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ECE 340 Homework V Fall 2003 Due: Wednesday, September 24, 2003 Solution: 30 points total 1. An p-type Si sample with N a = 2x10 16 /cm 3 is steadily illuminated such that g op = 10 21 EHP/cm 3-s. If τ n = τ p =1 μs for the excitation, calculate the separation in the quasi-Fermi levels, (F n-F p ). Draw a band diagram such as Fig. 4-11. Solution: (a) 15 3 1 10 op n p g c m δ δ τ − = = = × , therefore indeed low level injection 15 3 1 10 n n n cm δ − = + = × 16 3 2.1 10 p p p c m δ − = + = × 0.0259ln 0.288 n i i n F E eV n − = = 0.0259ln 0.366 i p i p E F e V n − = = 0.654 n p F F eV − = 2. (a) A Ge bar 0.1 cm long and 100 μm 2 in cross-sectional area is doped with 1x10 17 /cm 3 gallium. Find the current at 300 K with 10 V applied. Repeat for a Ge bar 1 μm long assuming that the saturation thermal velocity of electrons in Ge is about 10 7 cm/s. (b) Upon a steady illumination uniform excess carriers are generated in the Ge bar. Assume that τ n = τ p = 1 μs for the excitation. Estimate the optical generation rate of EHPs per second required to increase the 1 μs for the excitation....
View Full Document

This note was uploaded on 12/01/2011 for the course ECE 340 taught by Professor Lebutron during the Fall '03 term at University of Illinois, Urbana Champaign.

Page1 / 3

Ece340Fall03HW5sol - ECE 340 Homework V Fall 2003 Due Wednesday Solution 30 points total 1 An p-type Si sample with N a = 2x10 16/cm 3 is steadily

This preview shows document pages 1 - 2. Sign up to view the full document.

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