Voltage-controlled three terminal GaAs negative differential resistance device using n ⁺ -i-p ⁺ -i-n ⁺ structure

A novel three terminal GaAs n⁺-i-p⁺-i-n⁺ negative differential resistance device prepared by molecular beam epitaxy is demonstrated for the first time. The peak-to-valley current ratios can be modulated by the third external applied voltage which can be expressed as I_p/I_v = 5.08 × 10^-3 exp [1.999V_BE] at room temperature, where V_BE is in units of volts. It implies that large peak-to-valley current ratios (e.g. I_p/I_v = 300 at V_BE = 5.5 V) and large peak current densities can easily be obtained just by increasing the V_BE bias. A phenomenological bipolar-unipolar transition model is proposed to interpret the observed behavior and confirmed by experiments.