High-Voltage-Gain Hydrogen-Terminated Diamond Logic Inverter

This letter reports a high-voltage-gain hydrogen-terminated diamond logic inverter enabled by high-performance, high-k ZrO₂-gated diamond field-effect transistors (FETs). The ZrO₂ gate dielectric, with a high-k value of 20.3, ensures efficient electrostatic gating of the two-dimensional hole gas (2DHG) channel. This endows the driver FET with an ultrahigh on/off ratio of 2.13  10¹⁰ and fast switching speed with a low subthreshold swing of 86 mV/dec, which are critical for rapid transitions between the logic states of inverter. Consequently, the developed logic inverter demonstrates full swing output, sharp switching behavior with a record-high voltage gain of 422 among diamond-based logic inverters, and 1 kHz operation. This work paves the way for the practical application of diamond transistors and integrated circuits.