ece340Spring04HW9Sol - ECE 340 Homework IX Due: Wednesday,...

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

View Full Document Right Arrow Icon
ECE 340 Homework IX Spring 2004 Due: Wednesday, March 03, 2004 1. An abrupt Si p-n junction is formed by alloying a uniformly doped n-type silicon bar where N d = 8x10 16 /cm 3 in the beginning. During the alloying process, a uniform counter doping of acceptors of N a = 1.4x10 17 /cm 3 is introduced in the region for x<0. Basically, x<0 is the p-side and x>0 is the n-side. (a) Calculate the Fermi level positions at 300 K in the p and n regions. (b) Draw an equilibrium band diagram for the junction and determine the contact potential V o from the diagram. (c) Compare the results of part (b) with V o as calculated from Eq. (5-8). (d) Using Eq. (5-8), calculate and plot V o versus temperature ranging from 250 K to 500 K. Solutions: (a), At x<0, 16 3 61 0 pad p NN c m =−= × In p region, 16 10 0 ln 0.0259 ln 0.394 1.5 10 ip Fp i kT p E Ee V qn × −= = × = × In n region, 16 10 81 0 ln 0.0259 ln 0.401 1.5 10 Fn in i kT n E V × = × = × (b), V 0 = 0.795 V (c), Equations 5-8: 16 16 0 22 0 81 0 0.0259ln 0.0259ln 0.795 ad ii VV nn ×× × == = Result is same as (b) (d), Notice that the n i is related to temperature through Eq. 3-26 Method 1: Read n i from Figure 3-17, plug into Eqn 5-8 to obtain the plot.
Background image of page 1

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

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 4

ece340Spring04HW9Sol - ECE 340 Homework IX Due: Wednesday,...

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