Short-wave infrared indium gallium arsenide (InGaAs) detectors are crucial infrared devices, characterized by high quantum efficiency and high sensitivity at room temperature, thus finding extensive applications in aerospace remote sensing, industrial and agricultural production, security monitoring, biomedical imaging, and other fields. Dark current is a key performance parameter of short-wave infrared InGaAs detectors; reducing dark current under various bias voltages can enhance the detection capability of devices in different application scenarios. During the growth of semiconductor materials and the fabrication of devices, various types of defects are introduced, which affect the dark current and noise characteristics of the devices. In the development of photovoltaic devices, plasma hydrogenation technology can be utilized to passivate the surface or interface states of semiconductor materials through hydrogen. By eliminating the electrical activity of defects in semiconductor materials, photovoltaic cells can improve the quantum efficiency of semiconductor devices. However, there are few studies on the optimization of detector performance using plasma hydrogenation technology for room-temperature-operated PIN-type InGaAs detectors, especially regarding its impact on dark current mechanisms and noise. Therefore, this work focuses on the application of plasma hydrogenation technology in PIN-type InGaAs detectors. Room-temperature plasma hydrogenation technology was applied to the fabricated planar InGaAs detectors. A plasma etching machine was used to achieve hydrogen passivation of the devices. During the process, the devices were attached to the carrier with their photosensitive surfaces facing upward using vacuum silicone grease and placed inside the equipment chamber, i.e., the device surfaces were fully exposed to the hydrogen plasma atmosphere. The planar InGaAs detectors before and after hydrogenation were tested using an Agilent B1500A semiconductor analyzer to obtain their I-V characteristics. A current-voltage conversion amplifier and a lock-in amplifier were used to test the dark noise of the devices. To evaluate the impact of plasma hydrogenation on the response spectrum of the detectors, a Fourier transform infrared spectrometer and a current-voltage conversion amplifier were employed for testing.The relationship between hydrogenation and dark current mechanisms as well as noise characteristics was analyzed in combination with the measured data.The I-V test results showed that the dark current of the InGaAs detectors decreased significantly after the hydrogenation process (Fig.6). At a relatively large bias voltage of -1 V, the average dark current density decreased from 36.13 nA/cm² to 17.42 nA/cm²; under the near-zero bias condition of -0.02 V, the average dark current density decreased from 6.54 nA/cm² to 2.44 nA/cm². After room-temperature plasma hydrogenation, the dark current density under different bias voltages decreased by 2-3 times. Further analysis of the dark current mechanism revealed that the diffusion current, generation-recombination current, and shunt current were all suppressed to varying degrees (Fig.8). Diffusion current dominated in the bias range of 0 to -0.27 V both before and after hydrogenation, but the critical voltage where diffusion current dominates decreased by 0.15 V after hydrogenation. At large bias voltages, the proportion of shunt current increased slightly after hydrogenation. Since the minority carrier lifetime of InGaAs increased 6-fold from 10.7 μs to 75.2 μs after hydrogenation (Tab.1), and the zero-bias resistance increased by 1.75 times, the measured dark noise of the detectors decreased by approximately 40% (Tab.2).Through systematic electrical tests and analyses, the room-temperature plasma hydrogenation process effectively modified the dark current mechanism of PIN-type InGaAs detectors and improved the dark current levels of various components, with the three main current components decreasing by 2-3 times to varying degrees. By optimizing the minority carrier lifetime of InGaAs, the dark noise of the detectors was reduced by approximately 40%. Therefore, the application of room-temperature plasma hydrogenation holds significant technical reference value for the development of high-sensitivity InGaAs detectors.