Perovskite Resonant Tunneling FET with Sequential Negative Differential Resistance Peaks

A vertical resonant tunneling (RT) field effect transistor (VRTFET), fabricated using perovskite (CH3NH3PbI3), has been analyzed for sequential sharp negative differential resistance (NDR) peaks useful in multiple-valued logic devices. NDR peaks are attributed to the sub-bands formation within the parabolic shaped band gap, present at the channel and drain/source interface due to Schottky barriers. Ambipolar CH3NH3PbI3 imparts both p and n mode characteristics with RT NDR peaks. An unprecedentedly high (100 to 1000 V–1) curvature coefficient (ϒ) has been found with two NDR peaks at a short interval, whose positions shift left, with gate bias. Due to the ionic nature of CH3NH3PbI3, hysteresis has also been observed in the transfer characteristics. This structure can overcome the limit of 60 mV/decade as well as a curvature limit of 40 V–1, important parameters for analog and digital applications. So, these devices promise cheaper and easy fabrication at commercial scale operation at ultralow voltage and low power.