Resonant Tunneling Diode
Resonant tunneling, negative differential resistance, peak-to-valley current ratio
Parameters
1. Why does current decrease with increasing bias voltage after the RTD's peak (negative differential resistance)?
A. As bias increases, the double-barrier quantum well's resonant level shifts past the emitter conduction band edge, reducing the probability of resonant tunneling
B. The device heats up and breaks
C. Electrons stop moving
D. This is only a measurement artifact
2. What determines the energy of the resonant level in the quantum well?
A. The well width and the electron effective mass — a narrower well or a smaller effective mass gives a higher resonant energy
B. Only the applied voltage
C. Room lighting
D. The device's color
3. What does the peak-to-valley current ratio (PVCR) represent?
A. The ratio of peak to valley current — the higher it is, the "cleaner" the negative-resistance effect
B. The device's price
C. The temperature limit
D. The conduction band width
4. Where is the RTD's negative differential resistance used in practice?
A. In high-frequency (terahertz) oscillators, where negative resistance compensates for resistive losses in a resonant circuit
B. In solar panels
C. In mechanical clocks
D. In water filtration systems