Self-powered humidity sensors with high response and good stability have attracted extensive interest in environmental monitoring, medical and health care, and sentiment detection. Because of its high specific surface area and good conductivity, two-dimensional material has wide application in the field of humidity sensing. In this work, we proposed a novel self-powered high-performance TaS2/Cu2S heterostructure-based humidity sensor driven by a triboelectric nanogenerator (TENG) made with the same structure. The TaS2/Cu2S heterostructure was prepared via the chemical vapor deposition method, and then, electrolytic and ultrasound treatments were introduced to further increase the surface area. The fabricated humidity sensor showed ultrahigh sensitivity (S = 3.08 × 104), fast response (2 s), low hysteresis (3.5%), and great stability. First-principles calculation results demonstrated the existence of an electron transport channel with a low energy barrier (−0.156 eV) from the Cu2S to TaS2 layer in the heterostructure, which improves the surface charge transfer of the material. The TaS2/Cu2S heterojunction-based TENG can generate an output voltage of 30 V and an output current of 2.9 μA. Furthermore, the proposed self-powered humidity sensor verified the potential ability of detecting human respiratory frequency, skin humidity, and environmental humidity. This work provides a new and feasible path for research in the field of humidity sensors and promotes the application development of self-powered electronic devices.

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This work used the first-principles simulations to investigate interactions between orbital and electronic properties in the GaNm/AlNn quantum structure. By rotating the quantum well plane 90˚ from the c-plane, we delineated responses including a uniform bond length, an equal charge distribution on both well sides, and orbital changes at the quantum level near the valence band maximum (from the degenerated px/py to the separated py and pz). The found responses would positively contribute to wavelength reduction, quantum efficiency, and surface-emitting geometry. The tunable bandgap enables the production of electro-optic devices of Al-rich AlGaN for DUV applications.