Wide band gap semiconductors keep on pushing the limits of power electronic devices to higher switching speeds and higher operating temperatures, including diodes and transistors on low-cost Si substrates. Alternatively, erasable conducting walls created within ferroelectric single-crystal films integrated on the Si platform have emerged as a promising gateway to adaptive nanoelectronics in sufficient output power, where the repetitive creation of highly charged domain walls (DWs) is particularly important to increase the wall current density. Here, we observe large conduction of the head-to-head DW at an optimized inclination angle of 15° within a LiNbO3 single crystal that is 3-4 orders of magnitude higher than that of the tail-to-tail DW. The wall conduction is diode-like with a linear current density of higher than 1 mA/μm and an on/off ratio of larger than 106 under the application of a repetitive switching voltage pulse in time less than 10 ns and an endurance number of higher than 105. The high-power diodes can not only perform direct data processing in high-density nonvolatile DW memories in fast operation speeds and low-energy consumption but also function as sensors in compact electromechanical systems, selectors in phase-change memory and resistive random-access memory, and half-wave/full-wave rectifiers in modern nanocircuits in dimensions approaching the thickness of the depletion layer below which the tradition p-n junction malfunctions.
Keywords: LiNbO3 single crystal; current density; diode; domain wall; inclination angle; nanodevices.