Multifunctional Logic Gates via Coexistent Positive and Negative Photoconductivity of a Single Bi2Se3 Photodetector

Because existing electronic logic gates have some limitations in the era of information explosion, the demand for substantial amounts of data processing has aroused interest in new types of logic gates. The use of optoelectronic materials to prepare logic gates is popular; however, they often have complex structures, high power consumption, and low reliability. Herein, a new optoelectronic logic gate (OELG) is presented based on the coexistence of positive and negative photoconductivities in the 2D material Bi₂Se₃ at different wavelengths. Five logic gate signals (OR, AND, NOT, NOR, and NAND) can be modulated by inputting different wavelengths of light (405 and 808 nm) through a single Bi₂Se₃ photodetector, offering a new method for simple-structured OELGs. For practical applications, five logic gate output signals are modulated with 100% accuracy on an 8 × 8 pixel array, and simple imaging and logical processing of the images are demonstrated.