High-performance Si/VO_(2)-nanorod heterojunction photodetector based on photothermoelectric effect for detecting human radiation

As a typical candidate of optoelectronic materials,vanadium dioxide(VO_(2))has wide applications in photodetectors(PDs),but is still challenging in largely enhancing the photodetecting performance for low-power human radiation.Herein,high-performance Si/VO_(2)nanorods(NRs)heterojunction PDs based on the photothermoelectric(PTE)effect are presented.The uniform VO_(2)-NRs array films were deposited on Si by using magnetron sputtering technique,and a Si/VO_(2)heterojunctions were fabricated.The device exhibits a four-stage photoresponse and broadband photoresponse from ultraviolet to long-wavelength infrared.Benefited from the unique nanorods structure and the strong PTE effect,the fabricated device exhibits a large enhancement of the photodetecting performance,showing an ultrahigh photodetectivity of 1.6×10^(13)Jones and ultrafast response rates with a risingedge time of~65.0μs,three orders of magnitude higher than other VO_(2)-based devices.Furthermore,the device exhibits unique abilities to detect human radiation even when the human fingers are far away from the device surface up to 10.0 cm.Additionally,the fabricated Si/VO_(2)devices can also be applied as breath sensors to distinguish different breathing patterns.These results supply an effective route to design high-performance photodetectors toward detecting human thermal radiation and respiration.