Ohmic contact at 2D Bi2O2Se/TaNiTe5 interface via self-modulation doping

The quasi-2D Bi2O2Se has become a rising star in channel materials, but its contact resistance (RC) with metal still lags behind the requirements for advanced technology nodes. Here, ultra-low Schottky barriers and Ohmic contact are realized by integrating Bi2O2Se with 2D semimetal TaNiTe5, and excellent carrier injection efficiency is confirmed in the TaNiTe5/Bi2O2Se/TaNiTe5 stack. The physical mechanism we propose is reducing the work function of TaNiTe5 by intrinsic atom doping, and Ta doping is found to be most efficient because of its most delocalized charge density. These results and mechanisms are very meaningful for regulating the Schottky barrier height in 2D transistors to meet high performance and scalability requirements.