Two-Dimensional Heterostructure Complementary Logic Enabled by Optical Writing

Integrated logic circuits using atomically thin, two-dimensional (2D) materials offer several potential advantages compared to established silicon technologies such as increased transistor density, circuit complexity, and lower energy dissipation leading to scaling benefits. In this article, a novel approach to achieve tunable doping in 2D semiconductors is explored to achieve complementary transistors and logic integration. By selectively transferring WSe2 onto hBN and SiO2 substrates, complementary transistor behavior (n- and p-type) was achieved using a UV light source and electrostatic activation. Furthermore, advanced characterization techniques, including high-resolution transmission electron microscopy (HRTEM) and Kelvin probe force microscopy (KPFM), provided insights into the chemical composition and surface potential changes after UV writing. Finally, a logic inverter was successfully implemented using selectively photo-induced doped WSe2 transistors, showcasing the potential for practical logic applications. This innovative method opens new avenues for designing energy-efficient and reconfigurable 2D semiconductor circuits, addressing key challenges in modern electronics. We show complementary logic using a single flake of few layer WSe2 which has been transferred half on hBN and SiO2 substrates. Exposure of the flake to UV illumination with an applied negative gate voltage, manipulates the charge carrier type creating p- and n-type transistors. HRTEM shows the effect of the writing process, and a proof-of-concept logic inverter is demonstrated.image (c) 2024 WILEY-VCH GmbH