Photothermoelectric materials have important applications in many fields. Here, we joined a silver nanostructure film and a carbon nanotube film by van der Waals force to form a heterojunction, which shows excellent photothermal and photoelectric conversion properties. The local temperature difference and the output photovoltage increase rapidly when the heterojunction is irradiated by lasers with wavelengths ranging from ultraviolet to terahertz. The maximum temperature difference reaches 215.9 K, which is significantly higher than that of other photothermoelectric materials reported in the literature. The photothermal and photoelectric responsivity depend on the wavelength of lasers, which are 175~601 K W-1 and 9.35~40.4 mV W-1, respectively. We demonstrate that light absorption of the carbon nanotube is enhanced by local surface plasmons, and the output photovoltage is dominated by Seebeck effect. The proposed heterostructure can be used as high-efficiency sensitive photothermal materials or as ultra-wideband fast-response photoelectric materials.
Eutectic gallium-indium (EGaIn) alloy is a kind of liquid metal and has attracted much attention due to good properties. In order to satisfy the trend of miniaturization and realize more practical applications, the exploration for preparation method and properties of EGaIn at nanoscale are very important. Here, facile vacuum thermal evaporation method is developed to fabricate EGaIn nanostructures. The EGaIn nanoparticle and nanofilm with naturally formed 5 nm thick oxide layers are well prepared. The oxide film formed on the EGaIn surface is an important factor, making the properties of the nanostructure different from the properties of the bulk. Compared with ignorance of oxide layer in bulk materials, the proportion of oxide layer increases evidently in nanostructures, which produce obvious influence on the electric and optical properties. The rectifying characteristic and optoelectronic performance are experimentally observed. The EGaIn nanostructures can generate evident photocurrent responses with good responsivities (∼1 mA W −1 ) and response speed (∼1 s) under irradiation of 206 nm, 405 nm, 532 nm, 635 nm, 808 nm, 1064 nm and 10.6 μm lasers. These properties are completely different from the metallic properties of EGaIn bulk material.
Compared with CNT film detectors, the CsxWO3–CNT composite film detector shows a significantly enhanced photoresponse from visible light to short-wave infrared region, with an average increase of 400% in responsivity and 549% in specific detectivity.
Graphene is considered to be a valuable material in the field of photodetection due to its ultra-high electron mobility. However, weak light absorption, short carrier lifetime and lack of gain...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.