Electron And Hole Equilibrium Concentrations 24 February 2014  Return and discuss Quiz 2  Chapter 4 Topics-Two burning questions: What is the density.

Slides:



Advertisements
Similar presentations
Chapter 2-4. Equilibrium carrier concentrations
Advertisements

Chapter 2-3. States and carrier distributions
EE130/230A Discussion 2 Peng Zheng.
Lecture #5 OUTLINE Intrinsic Fermi level Determination of E F Degenerately doped semiconductor Carrier properties Carrier drift Read: Sections 2.5, 3.1.
Homogeneous Semiconductors
GOAL: The density of electrons (n o ) can be found precisely if we know 1. the number of allowed energy states in a small energy range, dE: S(E)dE “the.
The Semiconductor in Equilibrium (A key chapter in this course)
Semiconductor Device Physics
Lecture 2 OUTLINE Semiconductor Basics Reading: Chapter 2.
EE105 Fall 2007Lecture 1, Slide 1 Lecture 1 OUTLINE Basic Semiconductor Physics – Semiconductors – Intrinsic (undoped) silicon – Doping – Carrier concentrations.
Advanced Semiconductor Physics ~ Dr. Jena University of Notre Dame Department of Electrical Engineering SIZE DEPENDENT TRANSPORT IN DOPED NANOWIRES Qin.
CHAPTER 3 CARRIER CONCENTRATIONS IN SEMICONDUCTORS
Lecture #3 OUTLINE Band gap energy Density of states Doping Read: Chapter 2 (Section 2.3)
Read: Chapter 2 (Section 2.4)
Electron And Hole Equilibrium Concentrations 18 and 20 February 2015  Chapter 4 Topics-Two burning questions: What is the density of states in the conduction.
EXAMPLE 3.1 OBJECTIVE Solution Comment
Semiconductor Devices 22
EXAMPLE 8.1 OBJECTIVE To determine the time behavior of excess carriers as a semiconductor returns to thermal equilibrium. Consider an infinitely large,
Electron & Hole Statistics in Semiconductors More Details
Chapter 2 Semiconductor Materials and Diodes
Semiconductor Equilibrium
1. A photoresistor is formed from a square 1 cm x 1 cm slab of GaAs. Light of wavelength 830 nm falls onto it at a power density of 1, generating electron-hole.
Density of States and Fermi Energy Concepts
Numericals on semiconductors
Carrier Concentration in Equilibrium.  Since current (electron and hole flow) is dependent on the concentration of electrons and holes in the material,
ECE 340 Lecture 6 Intrinsic Material, Doping, Carrier Concentrations
Carrier Transport Phenomena And Measurement Chapter 5 26 February 2014
Semiconductor thermal statistics
Lecture 3 OUTLINE Semiconductor Fundamentals (cont’d) – Thermal equilibrium – Fermi-Dirac distribution Boltzmann approximation – Relationship between E.
Tutorial #4 – selected problems
Electron and Hole Concentrations in Extrinsic Semiconductor
Introduction to Semiconductor Technology. Outline 3 Energy Bands and Charge Carriers in Semiconductors.
BASICS OF SEMICONDUCTOR
Notes 27 February 2013.
President UniversityErwin SitompulSDP 2/1 Dr.-Ing. Erwin Sitompul President University Lecture 2 Semiconductor Device Physics
1 Prof. Ming-Jer Chen Department of Electronics Engineering National Chiao-Tung University September 18, 2014 DEE4521 Semiconductor Device Physics Lecture.
Carrier generation and recombination A sudden increase in temperature increases the generation rate. An incident burst of photons increases the generation.
Animation Demonstration No. 2. Interaction of Light with Semiconductors Normally a semiconductor material has only a few thermally excited free electrons.
Density of States (Appendix D) Energy Distribution Functions (Section 2.9) Carrier Concentrations (Sections ) ECE G201.
Manipulation of Carrier Numbers – Doping
Solid-State Electronics Chap. 4 Instructor: Pei-Wen Li Dept. of E. E. NCU 1 Chap 4. Semiconductor in Equilibrium  Carriers in Semiconductors  Dopant.
Homogeneous Semiconductors
EEE209/ECE230 Semiconductor Devices and Materials
© Electronics ECE 1312 EECE 1312 Chapter 2 Semiconductor Materials and Diodes.
Lecture 3 OUTLINE Semiconductor Fundamentals (cont’d)
Operational Amplifier
“Semiconductor Physics”
Manipulation of Carrier Numbers – Doping
Lecture 3 OUTLINE Semiconductor Fundamentals (cont’d)
Lecture 2 OUTLINE Important quantities
Materials Considerations in Semiconductor Detectors–II
Equilibrium carrier concentrations
Manipulation of Carrier Numbers – Doping

Lecture #5 OUTLINE Intrinsic Fermi level Determination of EF
Read: Chapter 2 (Section 2.3)
Lecture 3 OUTLINE Semiconductor Fundamentals (cont’d)
Basic Semiconductor Physics
Density of States (DOS)
Review of semiconductor physics
Energy Band Diagram (revision)
ECE 340 Lecture 6 Intrinsic Material, Doping, Carrier Concentrations
PHY 752 Solid State Physics Plan for Lecture 30: Chap. 13 of GGGPP
EE105 Fall 2007Lecture 1, Slide 1 Lecture 1 OUTLINE Basic Semiconductor Physics – Semiconductors – Intrinsic (undoped) silicon – Doping – Carrier concentrations.
Lecture 1 OUTLINE Basic Semiconductor Physics Reading: Chapter 2.1
Density of States (DOS)
Carrier Transport Phenomena And Measurement Chapters 5 and 6 22 and 25 February 2019.
Carrier Transport Phenomena And Measurement Chapters 5 and 6 13 and 15 February 2017.
Density of States (DOS)
Presentation transcript:

Electron And Hole Equilibrium Concentrations 24 February 2014  Return and discuss Quiz 2  Chapter 4 Topics-Two burning questions: What is the density of states in the conduction and valence bands? How do you find an exact position of the Fermi Level?

2 Concentration of Electrons at Equilibrium Thermal-equilibrium concentration of electrons (#/cm 3 ) in the conduction band Assume that E F is within the energy bandgap and So for energy levels in the conduction band there is (kT ≈ 25.9 meV for T=300K). So for energy levels in the conduction band Page 87 Text, Equation 3.69

5 5 Concentration of Electrons at Equilibrium Define effective density of states in the conduction band

7 7 Concentration of Holes at Equilibrium Thermal-equilibrium concentration of holes (#/m3) in the conduction band Assume that E F is within the energy bandgap and So for energy levels in the conduction band there is then for energy levels in the conduction band

8 8 Concentration of Holes at Equilibrium Define effective density of states in the valence band

10 Carrier Concentrations in Intrinsic Semiconductors For an intrinsic semiconductor, the concentration of electrons in the conduction band is equal to the concentration of holes in the valence band is the Fermi-level for the intrinsic semiconductor, i.e., intrinsic Fermi-level For a given semiconductor, at constant temperature, n i is constant

12 The Intrinsic Fermi-Level position If

Fermi-Energy Levels In Extrinsic Semiconductors

14 Electron and Hole Concentrations in Extrinsic Semiconductor Summary For both undoped material and doped material under equilibrium condition

15 Position of Fermi Energy in Extrinsic Semiconductors Position of Fermi-level:

16 Variation of Fermi-Energy with Doping Concentration

17 Variation of Fermi-Energy with Temperature