ZnO nanowire Schottky barrier ultraviolet photodetector with high sensitivity and fast recovery speed

Abstract

ZnO nanowire (NW) ultraviolet (UV) photodetectors have high sensitivity, while the long recovery time is an important limitation for its applications. In this paper, we demonstrate the promising applications of ZnO NW Schottky barrier as high performance UV photodetector with high sensitivity and fast recovery speed. The on/off ratio, sensitivity, and photocurrent gain are 4 × 105, 2.6 × 103 A/W, and 8.5 × 103, respectively. The recovery time is 0.28 s when photocurrent decreases by 3 orders of magnitude, and the corresponding time constant is as short as 46 ms. The physical mechanisms of the fast recovery properties have also been discussed.

Porosity-induced full-range visible-light photodetection via ultrahigh broadband antireflection in ZnO nanowires

“…ZnO can be easily synthesized in various 1D nanostructures [8][9][10][11][12] including nanowires (NWs), 13 nanotubes 14 and nanorods; 15 these structures have also shown promise in various nanoscale electronic and photonic devices, 16 such as photovoltaic cells, 17 light-emitting diodes, 18 gas sensors, 19 piezoelectric nanogenerators 20 and photodetectors. [21][22][23][24][25][26][27] However, with regard to photodetection, ZnO is only considered as a good material for UV photodetection 21,[23][24][25][26][27] owing to its wide band gap, and only a few studies have enabled ZnO to achieve limited visible light photodetection through doping or heterojunction structures. 22,28,29 This study is the first to demonstrate a new mechanism for obtaining a porosity-induced graded refractive index, which results in enhanced broadband antireflection properties, can extend the inherent properties of a 1D material, for example, the wide band gap of ZnO in this case, and can modify the material to enable improved visible-light photodetection over the entire visible-light regime.…”

Brush-like SnO2/ZnO hierarchical nanostructure: Synthesis, characterization and application in UV photoresponse

“…This device has a much faster time constant than most of ZnO UV photodetectors listed in the review paper. 48 After UV light turn-off, the photocurrent recovery process can also be fitted by an exponential expression I = I light exp(−t/τ d ), 16 τ d is the recovery time constant when the photocurrent decreases to its 1/e, the fitting result indicates a value of 2.16 s for τ d . The result indicates the hierarchical SnO 2 /ZnO nanostructure can be used as UV photodetector material.…”

“…9 From then on, nanosized optoelectronic devices were widely investigated. [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] Recently hierarchical nanostructure attract researchers' interests for its high surface-volume ratio which is benefit to improve the performance of the nanodevices. [26][27][28][29][30][31] Because of similar bandgap and optoeletronics functions of ZnO and SnO 2 , hybrid ZnO/SnO 2 threedimensional hierarchical nanostructures were fabricated and investigated.…”

One-Dimensional Zinc Oxide Nanomaterials for Application in High-Performance Advanced Optoelectronic Devices

“…In addition, the low dimensionality of the active area can shorten the transit time of carriers [4,106]. There are several types of photodetector structures, such as photoconductive, metal-semiconductor-metal (MSM), Schottky [107], and p-n junction [108][109][110] photodetectors.…”

“…To realize ZnO-based UV photodetectors with high sensitivity and fast response time, a Schottky contact instead of an ohmic contact was adopted [107,[112][113][114][115]. For example, Zhou and coworkers fabricated a Schottky junction-type photodetector that used ZnO nanowire and Pt metal electrode to form Schottky contact [98].…”