Guo Yidong, Qiu Yang, Zheng Shaonan, Zhong Qize, Dong Yuan, Zhao Xingyan, Hu Ting
Appl Opt. 2025 Jun 20;64(18):5115-5120. doi: 10.1364/AO.564072.
Lithium niobate (LN) photonic devices have been extensively explored due to their distinct material properties. However, the intrinsic wide bandgap and low electrical conductivity of LN prevent its direct application as a photodetection material at telecommunication wavelengths. In this work, a van der Waals heterostructure photodiode composed of a p-type palladium diselenide () layer and an n-type molybdenum disulfide () layer is successfully demonstrated for photodetection at communication wavelengths on a lithium niobate on insulator (LNOI) platform. The LN waveguide-integrated / photodetector exhibits an ultralow dark current of 0.5 nA, a high on/off current ratio of 180, and a responsivity of 0.77 mA/W at zero bias, highlighting its potential for self-powered photodetection. At -1 bias, the device maintains a dark current of only 23 nA while achieving a responsivity of 1.09 mA/W. An excellent linear photoresponse is observed over a wide power range (0.06-92.24 µW) under both zero- and reverse-bias conditions. These results demonstrate the potential of monolithically integrated LNOI photodetectors for high-performance optical communication and on-chip biochemical sensing applications.
铌酸锂（LN）光子器件因其独特的材料特性而得到了广泛研究。然而，铌酸锂的固有宽带隙和低电导率阻碍了其在电信波长下直接用作光电探测材料。在这项工作中，成功展示了一种由p型二硒化钯（）层和n型二硫化钼（）层组成的范德华异质结构光电二极管，用于在绝缘体上铌酸锂（LNOI）平台上进行通信波长的光电探测。集成了LN波导的/光电探测器在零偏压下表现出0.5 nA的超低暗电流、180的高开/关电流比和0.77 mA/W的响应度，突出了其自供电光电探测的潜力。在-1偏压下，该器件仅保持23 nA的暗电流，同时实现1.09 mA/W的响应度。在零偏压和反向偏压条件下，在很宽的功率范围（0.06 - 92.24 µW）内都观察到了出色的线性光响应。这些结果证明了单片集成LNOI光电探测器在高性能光通信和片上生化传感应用中的潜力。
