1 V LY3023414 cost for the V2O5 NW with d = 800 nm and l = 2.5 μm. The responsivity R is defined as the photocurrent generated by the power of light incident on an effective area of photoconductor, i.e., where P NW is the incident optical power on the projected area (A) of the measured NW and can be calculated as P NW = IA = Idl[29]]. The calculated R versus I result according to the measured i p values in Figure  2b is depicted in Figure  2c. The result shows that R selleckchem increases from 360 to 7,900 A W-1 gradually and saturates at a near-constant level while intensity decreases from 510 to 1 W m-2. While comparing the optimal R with that of earlier reports, the value at 7,900 A

W-1 is over one order of magnitude higher than that (R ~ 482 A W-1) of V2O5 NWs synthesized by hydrothermal approach [2]. Even if the comparison is made at similar power densities in the range 20 to 30 W m-2, the PVD-grown V2O5 NW still exhibits higher R at approximately find more 2,600 than the reference data by a factor of 5. In addition, compared to other nanostructured semiconductor photodetectors, the R of the V2O5 NW device is higher than those of ZnS NBs (R ~ 0.12 A W-1) [30], ZnSe

NBs (R ~ 0.12 A W-1) [31], ZnO nanospheres (R ~ 14 A W-1) [32], and Nb2O5 NBs (R ~ 15 AW-1) [33] and is lower than those of GaN NWs (R ~ 106 A W-1) [34] and ZnS/ZnO biaxial NBs (R = 5 × 105 A W-1) [35]. To investigate the Γ which is a physical quantity determining the photocarrier collection efficiency of a photodetector, Γ is estimated according to its linear relationship with R and i p, i.e., where E is the photon energy, e is the elementary electron charge, and η is the quantum efficiency [29].

To simplify the calculation, the η is assumed to be unity. The calculated Γ versus I result is also plotted in Figure  2c. The maximal Γ of this work at approximately 3 × 104 is also over one order of magnitude higher than that (Γ = 1328) of the hydrothermal-synthesized V2O5 NWs [2]. Compared with Loperamide other nanostructured semiconductor devices, the Γ of the V2O5 NW is higher than those of ZnS NBs (Γ ~ 0.5 A W-1) [30], ZnSe NBs (Γ ~ 0.4 A W-1) [31], ZnO nanospheres (Γ ~ 5 A W-1) [32], Nb2O5 NBs (Γ ~ 6 A W-1) [33], and WO3 NWs (Γ ~ 5×103 A W-1) [36] and is lower than those of ZnO NWs (Γ ~ 2 × 108 A W-1) [37], SnO2 NWs (Γ ~ 9 × 107 A W-1) [38], GaN NWs (Γ ~ 106 A W-1) [34], and ZnS/ZnO biaxial NBs (Γ = 2 × 106 A W-1) [35]. In addition, the power-dependent behavior of R (or Γ) could imply the potential hole trapping PC mechanism. The unintentionally doped V2O5 semiconductor has been confirmed to exhibit n-type conducting [6, 22, 39]. Under low power density, the photoexcited holes are totally captured by certain defects which function as a hole trap. The hole trapping effect leaves unpaired electrons which exhibit a long lifetime (τ). As photocurrent is linearly dependent on carrier lifetime, i.e.