Nanowires mediated growth ofβ-Ga_(2)O_(3)nanobelts for hightemperature(>573 K)solar-blind photodetectors

β-Ga_(2)O_(3),with ultra-wide bandgap,high absorption coefficient for high-energy ultraviolet(UV)photons,and high structural stability toward harsh-environment,has been receiving persistent attention for deep ultraviolet photodetectors applications.However,realization of devices with high tolerance toward high temperature faces great challenges due to considerable background signals mainly arising from abundant thermal excited carrier.Herein,nanowire-mediated high-qualityβ-Ga_(2)O_(3)nanobelts with ultra-thin thickness and length up to several hundred micrometers were achieved via a simple catalyst-free chemical vapor deposition route.The resulted microdevice output superior optoelectric figure of merits among numerous reports aboutβ-Ga_(2)O_(3),i.e.,ultra-low dark current(below the detection limit of 10−12 A),high responsivity(1,320 A/W),and high spectral selectivity working under low voltage(~2 V).More importantly,the performance remains robust at elevated temperature higher than 573 K.These results indicate a large prospect for low-voltage driven deep ultraviolet photodetectors with good sensitivity and stability at harsh environments.

Two-dimensional Bi_(2)O_(2)Se nanosheets for sensitive and fast-response high-temperature photodetectors

Two-dimensional Bi_(2)O_(2)Se with unique crystal structure and ultrahigh carrier mobility has been catching widespread attention and demonstrated great potential in nanoelectronic and optoelectronic devices.The existence of lattice oxygen ensures its ultrahigh stability at ambient environment and make it promising for high-temperature applications.Here,through systematical characterizations,the high air stability of Bi_(2)O_(2)Se nanosheets at temperatures up to 250℃is evidently demonstrated.The fabricated photodetectors based on the as-grown Bi_(2)O_(2)Se nanosheets show high stability,high sensitivity(~5319 A/Wat 250℃with a bias of 1 V)and fast response(several milliseconds)from room temperature to 250℃.Besides,it was observed that the devices also show good photoresponse covering UV,visible and infrared regions at high temperatures.These results suggest their promising high-performance applications serving under harsh conditions.

Transparent ultrathin SiO_(2) nanowire aerogel displaying novel properties when interacting with water:A promising versatile functional platform

With low density,high porosity,and outstanding physicochemical stability,ceramic nanowire aerogels and sponges exhibit various interesting properties.Herein,an ultrathin silica nanowire aerogel(SiO_(2)NWsA)was achieved via a facile chemical vapor deposition route.In addition to good mechanical and thermal performances,properties resulting from active water-aerogel interactions are revealed,i.e.,outstanding transparency,strong capillary effect,enhanced compressive strength(a reversible strain of∼62%),switchable wettability and robust shape retention ability when filled with water.The physical mechanism related to these interesting properties is demonstrated basically according to its unique features(distinctly reduced nanowire diameter,enriched nanoscopic gap channels,and reinforced network).To demonstrate the superiority,an advantageous solar vapor generation system(hydrophilic NWs-A/reduced graphene oxide(rGO)/hydrophobic NWs-A)was obtained by integrating these favorable characteristics,giving rise to remarkably promoted vapor evaporation rate and energy efficiency compared to the rGO hydrophobic NWs-A device.These results contribute to the structural design and functional exploration of nanowire aerogels.

Multi-time scale photoelectric behavior in facile fabricated transparent and flexible silicon nanowires aerogel membrane

In recent years,transparent and flexible materials have been widely pursued in electronics and optoelectronics fields for usage as planar electrodes,energy conversion components and sensing units.As the most widely applied semiconductor material,the related progress in silicon is of great significance although with large difficulty.Herein,we report a one-step method to achieve flexible and transparent silicon nanowires aerogel membrane.A competitive carrier kinetics involving interfacial trapped carriers and the valence electrons transition is demonstrated,according to the photoelectric performance of a sandwiched graphene/silicon nanowires membrane/AI device,i.e.,rapidly positive photoresponse dominated by laser excited^ee-carriers generation(〜500 ms)and subsequent slow negative photocurrent evolution due to laser heating involved multi-levels process(>10 s).These results contribute to fabrication of silicon nanowire self-assembly structures and also the exploration of their optoelectrical properties in flexible and transparent devices.