Evac Evac 1 1 qc1 = 4.07 eV qfs1 = 4.782 eV qc2 = 3.63 eV qfs2 1 1 qc1 = 4.07 eV qfs1 = 4.782 eV qc2 = 3.63 eV qfs2 = 4.592 eV 2 2 3 3 EC2 4 4 EC1 Eg2 = 1.923 eV EF2 EF1 Eg1 = 1.424 eV 5 5 EV2 EV1 6 6 VM Ayres, ECE802-604, F13

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, ECE802-604, F13

Align Fermi energy levels: EF1 = EF2: VM Ayres, ECE802-604, F13

Put in Junction J in middle since both undoped (intrinsic): VM Ayres, ECE802-604, F13

Join Evac smoothly: Junction J VM Ayres, ECE802-604, F13

Anderson Model: Use qc1 “measuring stick” to put in EC1: Junction J VM Ayres, ECE802-604, F13

Anderson Model: Use qc2 “measuring stick” to put in EC2: Junction J VM Ayres, ECE802-604, F13

Put in straight piece connector: Junction J DEC = 0.44 eV Anderson model: DEC = qc1 – qc2 = 0.44 eV VM Ayres, ECE802-604, F13

A shallow quantum well for e- has developed in the conduction band EC1: Junction J DEC = 0.44 eV VM Ayres, ECE802-604, F13

Use the energy bandgap Eg1 “measuring stick” to relate EC1 and EV1: Junction J DEC = 0.44 eV VM Ayres, ECE802-604, F13

Use the energy bandgap Eg2 “measuring stick” to relate EC2 and EV2: Junction J VM Ayres, ECE802-604, F13

Put straight piece connector in: Junction J DEC = 0.059 eV Anderson model: DEgap = DEC + DEV => DEV = DEgap – DEC DEV = [(1.923 – 1.424) – 0.44] eV = 0.059 eV VM Ayres, ECE802-604, F13

A very shallow quantum well for holes has developed in EV2: Junction J DEC = 0.059 eV VM Ayres, ECE802-604, F13

(a) Band-bending diagram: Junction J DEC = 0.44 eV DEV = 0.059 eV (b) Anderson model: DEC = 0.44 eV DEV = 0.059 eV VM Ayres, ECE802-604, F13

Result is similar to n-n and p-p isotype heterojunctions: Sze, Physics of Semiconductor Devices VM Ayres, ECE802-604, F13

These are the traditional n-p and p-n heterojunctions: Sze, Physics of Semiconductor Devices VM Ayres, ECE802-604, F13