All‐Optic Logical Operations Based on the Visible‐Near Infrared Bipolar Optical Response

• Published in: Advanced science 2024-10, Vol.11 (40), p.e2404336-n/a
• Main Authors: You, Jie, Han, Zhao, Zhang, Ningning, Zhang, Qiancui, Zhang, Yichi, Liu, Yang, Li, Yang, Ao, Jinping, Jiang, Zuimin, Zhong, Zhenyang, Guo, Hui, Hu, Huiyong, Wang, Liming, Zhu, Zhangming
• Format: Article
• Language: English
• Subjects: all‐optic logical; bipolar optical response; Circuits; Logic; Microscopy; Optics; Photonics; reduction transistor number; Semiconductors; Signal processing; Transistors
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202404336

The burgeoning need for extensive data processing has sparked enthusiasm for the development of a novel optical logic gate platform. In this study, junction field‐effect phototransistors based on molybdenum disulfide/Germanium (MoS2/Ge) heterojunctions are constructed as optical logic units. This device demonstrates a positive photoresponse that is attributed to the photoconductivity effect occurring upon irradiation with visible (Vis) light. Under the illumination of near‐infrared (NIR) optics with wavelengths within the communication band, the device shows a negative photoresponse, which is associated with the interlayer Coulomb interactions. The current state of the device can be effectively modulated as different logical states by precisely tuning the wavelength and power density of the optical. Within a 3 × 3 MoS2/Ge phototransistor array, five essentially all‐optical logic gates (“AND,” “OR,” “NAND,” “NOT,” and “NOR”) can be achieved in every signal unit. Furthermore, three complex all‐optical logical operations are demonstrated by integrating two MoS2/Ge phototransistors in series. Compared to electronic designs, these all‐optical logic devices offer a significant reduction in transistor number, with savings of 50–94% when implementing the above‐mentioned functions. These results present opportunities for the development of photonic chips with low power consumption, high fidelity, and large volumes. Ge/MoS2 JFET demonstrates a remarkable bipolar optical response in the visible and infrared spectrum, achieving various essentially and complex all‐optical logic operations. Compared with traditional electronic circuits, all‐optical devices reduce the number of transistors by more than 50%. Capitalizing on these distinctive characteristics, this device holds immense promise for innovative all‐optical image processing.