1. Evac Evac 1 1 qc1 = 4.07 eV qfs1 = 4.782 eV qc2 = 3.63 eV qfs21 1
qc1
= 4.07 eV
qfs1
= eV
qc2
= 3.63 eV
qfs2
= eV 2 2 3 3
EC2 4 4
EC1
Eg2
= eV
EF2
EF1
Eg1
= eV 5 5
EV2
EV1 6 6
VM Ayres, ECE , F13

2. Now that plots are accurately scaled, remove values for clarity.
Evac
Evac
EC2
EC1
EF2
EF1
EV2
EV1
Now that plots are accurately scaled, remove values for clarity.
VM Ayres, ECE , F13

3. Align Fermi energy levels: EF1 = EF2:
VM Ayres, ECE , F13

4. Put in Junction J in middle since both undoped (intrinsic):
VM Ayres, ECE , F13

5. Join Evac smoothly:
Junction J
VM Ayres, ECE , F13

6. Anderson Model: Use qc1 “measuring stick” to put in EC1:
Junction J
VM Ayres, ECE , F13

7. Anderson Model: Use qc2 “measuring stick” to put in EC2:
Junction J
VM Ayres, ECE , F13

8. Put in straight piece connector:
Junction J
DEC
= 0.44 eV
Anderson model:
DEC = qc1 – qc2 = 0.44 eV
VM Ayres, ECE , F13

9. A shallow quantum well for e- has developed in the conduction band EC1:
Junction J
DEC
= 0.44 eV
VM Ayres, ECE , F13

10. Use the energy bandgap Eg1 “measuring stick” to relate EC1 and EV1:
Junction J
DEC
= 0.44 eV
VM Ayres, ECE , F13

11. Use the energy bandgap Eg2 “measuring stick” to relate EC2 and EV2:
Junction J
VM Ayres, ECE , F13

12. Put straight piece connector in:
Junction J
DEC
= eV
Anderson model:
DEgap = DEC + DEV => DEV = DEgap – DEC
DEV = [(1.923 – 1.424) – 0.44] eV = eV
VM Ayres, ECE , F13

13. A very shallow quantum well for holes has developed in EV2:
Junction J
DEC
= eV
VM Ayres, ECE , F13

14. (a) Band-bending diagram:
Junction J
DEC
= 0.44 eV
DEV
= eV
(b) Anderson model:
DEC = 0.44 eV
DEV = eV
VM Ayres, ECE , F13

15. Result is similar to n-n and p-p isotype heterojunctions:
Sze, Physics of Semiconductor Devices
VM Ayres, ECE , F13

16. These are the traditional n-p and p-n heterojunctions:
Sze, Physics of Semiconductor Devices
VM Ayres, ECE , F13