Resonant Tunneling Diodes (RTD)
Concept of Resonant Tunneling An interesting phenomena occurs when two barriers of width a separated by a potential well of a small distance 𝐿 as shown in fig. This leads to the concept of resonant tunneling. Fig.: Double barrier junction with no applied bias. The barriers are sufficiently thin to allow tunneling and the well region between the two barriers is also sufficiently narrow to form discrete (quasi-bound) energy levels. The transmission coefficient of the double symmetric barrier becomes unity. (ie., T = 1) , when the energy of the incoming electron wave ( 𝐸 ) coincides with the energy of one of the discrete states formed by the well. Thus, transmission probability of the double symmetric barrier is maximum; hence, the tunneling current reaches peak value when the electron wave's energy is equal to the well's quantized energy state. This phenomenon is known as resonance tu...