1. Mid-term Exam
10/23 (Thurs)
Closed book but bring a cheat sheet and a calculator
No class this Thurs.

2. Lecture 10 Solid-Liquid Interface -Part II-
Reference.
R. Memming, Semiconductor Electrochemistry, Wiley-VCH, 2000 (e-book)
A.J. Bard and L.R. Faulkner, Electrochemical Methods: Fundamentals and Applications, Wiley, 2001
J. O’M. Bockris, A.K.N. Reddy, and M. Gamboa-Aldeco, Modern Electrochemistry, Kluwer Academic/Plenum Publishers, 2000
Lecture note

3. Charge and Potential Distribution at the Interface
Now you have a charge distribution at the interface.
Then what happens at the interface?
OK. Now you replace a metal electrode with a semiconductor.
Then, how would the charge distribution change?
Now the charges will be distributed in 1) 2) 3)

4. Semiconductor-Electrolyte Interface

5. The Mott-Schottky Plot

6. Electrode Potential vs. pH

7. Flatband Potential of n- vs. p-type SC

8. Flatband Potential of n-SC

9. Flatband Potential of p-SC

10. The electrode potential UE measured vs. a ref. electrode is
UE = Dfsc + DfH + const
Now, you apply a bias to the SC electrode.
Then, how does this applied bias would change the potential distribution at the semiconductor/electrolyte interface?

11. Band Diagram of SC-Electrolyte Interface
- Band Edge Pinning -

12. Band Edge Positions of Semiconductors

13. Unpinning of Energy Bands during Illumination

15. Semiconductor-Electrolyte Interface
Charge distribution in a semiconductor and electrolyte
Potential drop in a semiconductor
Flatband potential (vs. pH)
Band edge pinning

16. Next Meeting
Mid-term exam