{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Electronics-I Lecture 12

Electronics-I Lecture 12 - Freeelectrons Freeholes...

Info icon This preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 12 Electronics I 1 Basic Semiconductor Concepts Thermal Ionization results in Free electrons Free holes Equal number Move randomly through silicon crystal Recombination Free electrons and holes combine Recombination rate proportional to number of free  electrons and holes which is proportional to ionization  rate
Image of page 1

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

View Full Document Right Arrow Icon
Lecture 12 Electronics I 2 Basic Semiconductor concepts Ionization rate is a strong function of  temperature In thermal equilibrium, recombination rate  is equal to ionization  n = p = n i  (concentration of holes or  electrons in intrinsic silicon/cm 3 ) kT / E 3 2 i G e BT n - =
Image of page 2
Lecture 12 Electronics I 3 Basic Semiconductor concepts B material dependant parameter = 5.4 x 10 31  for Silicon E G  bandgap energy = 1.12 eV for Silicon k Boltzmann’s constant = 8.62 x 10 -5  eV/K At room temperature (T = 300 K)  n i = 1.5 x 10 10  carriers/cm 3 Silicon crystal has 5 x 10 22  atoms/cm 3   At room temperature only one of every billion atom is  ionized kT / E 3 2 i G e BT n - =
Image of page 3

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

View Full Document Right Arrow Icon
Lecture 12 Electronics I 4 Basic Semiconductor concepts Diffusion and Drift Two mechanisms by which electrons/hole move through a silicon  crystal Diffusion Random motion due to thermal agitation cause uniform  concentration of holes and free electrons
Image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern