Gigahertz Integrated Circuits Based on Complementary Black Phosphorus Transistors

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AbstractBlack phosphorus (BP) has attracted enormous interest for logic applications due to its unique electronic properties. However, pristine BP exhibits predominant p‐type channel conductance, which limits the realization of complementary circuits unless an effective n‐type doping is found. Here, a practical approach to transform the conductivity of BP from p‐type to n‐type via a spatially controlled aluminum (Al) doping is proposed. Symmetrical threshold voltage for the pair of p‐type and n‐type BP field‐effect transistors can be achieved by tuning the Al doping concentration. The complementary inverter circuit shows a clear logic inversion with a high voltage gain of up to ≈11 at a supply voltage (VDD) of 1.5 V. Simultaneously, a high noise margin of 0.27 × VDD is achieved for both low (NML) and high (NMH) input voltages, indicating excellent noise immunity. Moreover, a three‐stage ring oscillator with a theoretical frequency above 1.8 GHz and microwatt level power dissipation is modeled, which shows a low propagation delay per stage. This study demonstrates a practical approach to fabricate high performance complementary integrated circuits on a homogenous BP channel material, paving the way toward complex cascaded circuits and sensor interface applications.