Ultrabroadband photodetectors are essential for applications such as biomedical imaging, environmental assessment, optical data transmission, gas detection, and security monitoring. However, traditional semiconductor detectors are typically limited to detection within a single spectral range, and achieving ultrabroadband detection often requires integrating multiple detectors. This is particularly challenging in the terahertz range, where detection is constrained by high dark currents and the need for cryogenic cooling. As a result, expanding the detection range has become a critical focus in optoelectronic development. In this study, we successfully demonstrated ultrabroadband detection from the visible to terahertz spectrum at room temperature using a heterojunction formed by Ta₂NiSe₅ and graphene, driven by multiple physical mechanisms. The detector leverages the combined effects of photoexcited electron–hole pairs and the photothermal response triggered by the asymmetry of the heterojunction, achieving responsivities of 4.8 mA/W at 638 nm, 3.8 mA/W at 1550 nm, 42.9 mA/W at 0.12 THz, and 14.6 mA/W at 0.3 THz. Additionally, the device achieves NEP values as low as 7 pW/Hz^1/2 at 0.12 THz and 23 pW/Hz^1/2 at 0.3 THz, with a response time of 7.4 μs at 0.12 THz. Our findings demonstrate a novel approach to ultrabroadband detection, achieving high sensitivity and fast response by leveraging multiple physical mechanisms. This work opens new avenues for the future development of optoelectronic detection technologies.

中文翻译：

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多机制驱动的 Ta2NiSe5-石墨烯异质结，用于从可见光到太赫兹光谱的超宽带检测


超宽带光电探测器对于生物医学成像、环境评估、光学数据传输、气体检测和安全监控等应用至关重要。然而，传统的半导体探测器通常仅限于在单个光谱范围内进行检测，而实现超宽带检测通常需要集成多个探测器。这在太赫兹范围内尤其具有挑战性，因为检测受到高暗电流和低温冷却需求的限制。因此，扩大检测范围已成为光电发展的关键重点。在这项研究中，我们成功地展示了在室温下使用由 Ta₂NiSe₅ 和石墨烯形成的异质结，在多种物理机制的驱动下，从可见光到太赫兹光谱的超宽带检测。该探测器利用光激发电子-空穴对和异质结不对称性触发的光热响应的综合效应，实现了 638 nm 时 4.8 mA/W、1550 nm 时 3.8 mA/W、0.12 THz 时 42.9 mA/W 和 0.3 THz 时 14.6 mA/W 的响应度。此外，该器件在 0.12 THz 时可实现低至 7 pW/Hz^1/2 的 NEP 值，在 0.12 THz 时可实现低至 23 pW/Hz^1/2 的 NEP 值在 0.3 THz 时，在 0.12 THz 时的响应时间为 7.4 μs。我们的研究结果展示了一种新的超宽带检测方法，通过利用多种物理机制实现高灵敏度和快速响应。这项工作为光电检测技术的未来发展开辟了新的途径。