**ECE**** 135B Electronic Devices**

**Spring Quarter, March 30 – June 16, 2017**

**University of California San Diego**

**Department of Electrical and Computer Engineering**

**Instructor: **Prof. Shadi Dayeh

Office: Jacobs Hall (EBU1), Room 3609

Tel.: (858) 534-5171; Fax: (858) 534-0556; e-mail: sdayeh@ucsd.edu

Office Hours: Wednesday 2:00 pm - 3:00 pm and by appointment.

**Lectures:** Tuesday, Thursday 3:30 pm - 4:50 pm WLH, Room 2208.

_ **Announcements:**

- 04/12/2017: Welcome to ECE135B! Please check this website regularly for announcements and class related handouts.

- 04/12/2017: In today’s lecture, we discussed absorption in semiconductors, optical generation processes, and recombination processes.

- 04/18/2017: In today’s lecture, we went over the design requirements for solar cells and setting up the boundary conditions to solve for the minority carrier concentration and then solved the continuity (diffusion) equation to obtain the minority carrier profiles. We then obtained the solar cell current voltage characteristics and the small signal model and discussed the maximum power point, the fill factor, the power conversion efficiency, internal quantum efficiency, and external collection/quantum efficiency.

- 04/20/2017: In today’s lecture, we went over the effects of series and shunt resistance on the solar cell performance and over homework # 2. Homework #2 was handed out in class and is due on 5/2/17.

- 04/25/2017: In today’s lecture, we discussed MIS capacitors, the potential and carrier density as a function of distance in an MOS capacitor, and solved the 1D Poisson’s equation to calculate the electric field and charge density in the semiconductor as a function of surface potential.

- 04/27/2017: In today’s lecture, we went over regional approximations for the electric field, potential, and charge density in MIS structures and then derived the MIS capacitance and discussed the capacitance-voltage characteristics together with regional approximations. We also went over the interface state capacitance and how to extract the interface state density using the Terman method.

- 05/02/2017: In today’s lecture, we discussed the flat band voltage and then started the MOSFETs with energy band edge diagram analysis, gradual channel approximation for current equation derivation and started discussion about the gradual channel approximation.

- 05/02/2017: **Homework # 3 is handed out today and will be due on the 11 ^{th}. The midterm will take place on the 16^{th} and will cover materials up to and including the MIS capacitors. You can use a single sided cheat sheet, A4 size, and you need a blue book, pen, and calculator.**

- 05/02/2017: In today's lecture, we continued our discussions on the charge sheet model and went on to the regional approximations. We derived a general equation for the current within the charge sheet model and then assumed that the surface potential and the Qs do not change beyond strong inversion in order to simplify Qi and d(Psi_s)/dx. We discussed the linear triode/regime, parabolic regime, and the saturation pinch-off regime and introduced the body factor concept and evaluated the threshold voltage. We also discussed the change of the inversion charge with the V(y), the lateral quasi-Fermi potential in the channel.

- 05/09/2017: In today's lecture, we reviewed the results of the derivations for the Ids(Vgs,Vds) in the spirit of charge-sheet model and regional approximations. We then looked one more time at the dependence of -Qi on the lateral quasi-Fermi level (V(y)), and on V(y) as a function of L at different Vds bias. We then derived an equation for the subthreshold current and discussed the subthreshold slope and how it is influenced by Dit. We then discussed the short channel effect embodied in a threshold voltage roll-off and drain-induced barrier lowering (DIBL).

- 05/12/2017: In today's lecture, we continued the discussion on short channel MOSFETs and worked with velocity saturation and derived the current equations in the velocity saturation limit and briefly overviewed the channel length modulation.

**- ** 05/12/2017: We will have our midterm on May 16. It will cover materials up to and including the MIS capacitors. You can use a single sided cheat sheet, A4 size, and you need a blue book, pen, and calculator.

**- 05/16/2017: Our midterm and its solutions have been posted below for your reference. Also, Homework # 4 has been assigned. You can start on problems 2 & 3 and I will help you in problem 1 once we meet in class on May 25th. **

**- 05/25/2017: In today's lecture, we went over the capacitances in MOSFETs, transit time and cut off frequency. We then started BJTs with introductory notes about transistor action and carrier profiles and their contribution to current. **

**-- 06/01/2017: For BJT's, we covered the minority carrier profiles, transistor action, current equations, figures of merit, non-idealities, and current-voltage characteristics. You will not be responsible for BJTs for the final. The lecture notes are updated below. **

_ **Lecture Notes:**

- 04/13/2017: Lecture1.1

- 04/13/2017: Lecture1.2

- 04/13/2017: Lecture1.3

- 04/13/2017: Lecture2.1

- 04/13/2017: Lecture2.2

- 04/20/2017: Lecture2.3

- 04/25/2017: Lecture3.1

- 04/27/2017: Lecture3.2

- 05/02/2017: Lecture3.3 Lecture4.1

- 05/04/2017: Lecture4.2

- 05/09/2017: Lecture4.3

- 05/09/2017: Lecture4.4

- 05/09/2017: Lecture4.5

- 05/09/2017: Lecture5.1

- 06/01/2017: BJTs

_ **Handouts:**

** **

- 04/13/2017: Chapter 3 of Handbook of Photovoltaic Science and Engineering, The Physics of the Solar Cell

- 04/13/2017: Absorption in Si (for Homework # 2)

- 04/13/2017: Midterm-sample Midterm-sample Solution

- 04/13/2017: ECE103 Lecture Notes

- 04/13/2017: Final-Exam-sample Final-Exam-sample-Solutions

- 05/16/2017: Midterm Midterm Solutions

_ **Problem Sets and Solutions:**

- 04/12/2017: Homework # 1 (due 04/14/2017) Homework # 1 Solutions

- 04/20/2017: Homework # 2 (due 05/04/2017) Homework # 2 Solutions

- 05/4/2017: Homework # 3 (due 05/11/2017) Homework # 3 Solutions

- 05/16/2017: Homework # 4 (due 05/11/2017) Homework # 4 Solutions

© Shadi Dayeh, 2017 Last update: 06/06/2017 7:50 pm.