近日，西北工业大学甘雪涛团队研究了具有非易失性p-i-n同质结的片上石墨烯光电探测器。这一研究成果于2025年7月7日发表在《光：科学与应用》上。

石墨烯独特的光热电（PTE）效应，加上其片上制造的兼容性，使其有望在具有超低暗电流和超快速度的芯片集成光电探测器中得到发展。先前的片上石墨烯光电探测器设计需要外部电偏置或门电压来分离光载流子，导致功耗增加和电路复杂。

研究组展示了在硅光子晶体波导上构建的非易失性石墨烯p-i-n同质结，它有助于基于PTE的光检测，而不需要电偏置或门电压。通过将气缝光子晶体波导设计为两个独立的硅后门，并采用具有残余极化场的铁电介质，电配置了具有明显塞贝克系数梯度的非易失性p-i-n同质结。石墨烯通道中的热载流子由波导倏逝场吸收产生，通过非易失性p-i-n同质结有效分离，产生可观的光电流。

在零偏压、零栅压条件下，集成在光波导上的这种非易失性石墨烯p-i-n同质结光电探测器展现出优异的性能：在1560–1630纳米宽带波长范围内具有193毫安/瓦的高且平坦的响应度，并在仪器测量极限下测得17吉赫的超快动态响应带宽。利用高性能片上光电检测技术，直接构建在硅光子电路上的非易失性石墨烯同质结有望扩展光电子突触、内存传感和计算以及神经形态计算的片上功能。

附：英文原文

Title: On-chip graphene photodetectors with a nonvolatile p–i–n homojunction

Author: Tian, Ruijuan, Zhang, Yong, Ji, Yingke, Li, Chen, Wu, Xianghu, Wang, Jianguo, Jia, Shuaiwei, Liu, Liang, Zhang, Mingwen, Zhang, Yu, Zhang, Qiao, Xie, Zhuang, Luo, Zhengdong, Gao, Duorui, Liu, Yan, Zhao, Jianlin, Sun, Zhipei, Gan, Xuetao

Issue&Volume: 2025-07-07

Abstract: Graphene’s unique photothermoelectric (PTE) effect, combined with its compatibility for on-chip fabrication, promises its development in chip-integrated photodetectors with ultralow dark-current and ultrafast speed. Previous designs of on-chip graphene photodetectors required external electrical biases or gate voltages to separate photocarriers, leading to increased power consumption and complex circuitry. Here, we demonstrate a nonvolatile graphene p–i–n homojunction constructed on a silicon photonic crystal waveguide, which facilitates PTE-based photodetection without the need for electrical bias or gate voltages. By designing an air-slotted photonic crystal waveguide as two individual silicon back gates and employing ferroelectric dielectrics with remnant polarization fields, the nonvolatile p–i–n homojunction with a clear gradient of Seebeck coefficient is electrically configured. Hot carriers in the graphene channel generated from the absorption of waveguide evanescent field are separated by the nonvolatile p–i–n homojunction effectively to yield considerable photocurrents. With zero-bias and zero-gate voltage, the nonvolatile graphene p–i–n homojunction photodetector integrated on the optical waveguide exhibits high and flat responsivity of 193mAW1 over the broadband wavelength range of 1560–1630nm and an ultrafast dynamics bandwidth of 17GHz measured in the limits of our instruments. With the high-performance on-chip photodetection, the nonvolatile graphene homojunction directly constructed on silicon photonic circuits promises the extended on-chip functions of the optoelectronic synapse, in-memory sensing and computing, and neuromorphic computing.

DOI: 10.1038/s41377-025-01832-y

Source: https://www.nature.com/articles/s41377-025-01832-y