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The author reported the AlGaZnO photodetector characteristics with various AGO:ZnO co-sputtering power ratio. It was found the optimized on/off ratio and responsivity were about $3.64 \times 10^{5}$ and 0.15 A/W, respectively, at the 10 V applied bias, and with AGO:ZnO power ratio of 80 W:50 W. The UV to visible rejection ratio was $8.08 \times 10^{3}$ , indicated the significant response under UV illumination. The on/off ratio and responsivity could further be improved to $4.2 \times 10^{6}$ and 0.44 A/W, respectively, by annealed at 300°C for an hour, to decrease the defect in the AGZO film. Besides, the photoresponse of the AGZO photodetectors also showed a repeatable and stable switching characteristic. These results indicate the performance of AGZO photodetector were good, and can be a good candidate for low cost, fast fabricated solar-blind application. [ABSTRACT FROM AUTHOR]

The authors report the deposition of an (AlxGa1-x)2O3 amorphous thin film on sapphire substrates by sputter deposition. An amorphous deep ultraviolet (UV) (Al0.12Ga0.88)2O3 photodetector, with a cutoff wavelength at 230 nm, was also fabricated. With −10 V applied bias, it was found the dark leakage current and the linear dynamic range (LDR) of the fabricated photodetector were about 1.23 × 10−9 A and 59.51 dB, respectively. With the same −10 V applied bias, the UVC/UVA contrast ratio was larger than 20. With λillumination = 230 nm and −5 V applied bias, it was found noise equivalent power (NEP) and detectivity (D*) of the fabricated amorphous deep UV (Al0.12Ga0.88)2O3 photodetector were 9.94 × 10−11 W and 2.11 × 1010 cmHz1/2W−1, respectively. These results suggest the fabricated amorphous deep UV (Al0.12Ga0.88)2O3 photodetector herein indicate a cost-effective solution for developing DUV photodetector applications. [ABSTRACT FROM AUTHOR]

The vapor cooling condensation system was utilized to deposit the homostructured n-ZnO:In/i-ZnO/p-ZnO:LiNO3 and heterostructured n-ZnO:In/i-Zn3Ta2O5/p-ZnO:LiNO3 on sapphire substrates. The zero bias dynamic resistance of the latter ones was improved to 2.43\times 10^12 ~\Omega compared with 7.94\times 10^11 ~\Omega of the former ones. Using the photoelectrochemical (PEC) oxidation method to treat the heterostructured n-ZnO:In/i-Zn3Ta2O5/p-ZnO:LiNO3 ultraviolet photodetectors, the zero bias dynamic resistance was further improved to 6.02\times 10^12~\Omega . The sensing and the noise performances of the ultraviolet photodetectors were effectively improved by the Zn3Ta2O5 absorption layer and the PEC oxidation method. [ABSTRACT FROM PUBLISHER]

The structure of the ZnO-based p-ZnO:LiNO3/i-ZnO/n-ZnO:In nanorod ultraviolet (UV) photodetectors was grown on sapphire substrates using the vapor cooling condensation system. To study the internal gain mechanisms of the photodetectors, the ZnO-based nanorods were photochemically passivated for different time and operated under various environments to vary the defect density resided on the sidewall surface of the ZnO-based nanorods. The mechanisms of the internal gain, which was attributed to the surface band bending effect of the ZnO-based nanorods induced from the sidewall surface defects and the absorbed oxygen molecules, were thus derived. The specific detectivity of 3.25\times 10^15 cmHz ^\mathrm 1/2\textW^-1 was obtained for the ZnO-based nanorod UV photodetectors treated with the photoelectrochemical passivation process for 2 min. [ABSTRACT FROM PUBLISHER]

The n-ZnO/i-ZnO nanorod arrays were deposited on p-GaN layer using the vapor cooling condensation system. The photoelectrochemical system was used to directly grow thin Zn(OH) _2layer for passivating sidewall surface of the ZnO nanorod arrays. The resultant surface leakage current, the thermal noise current, and the shot noise current of the passivated ZnO nanorod array photodetectors were reduced compared with the unpassivated ZnO nanorod array photodetectors. The mean square noise current of the passivated ZnO nanorod array photodetectors was smaller than that of the unpassivated ZnO nanorod array photodetectors. These experimental results verified that the reliability and stability of the passivated ZnO nanorod array photodetectors were improved compared with the unpassivated ZnO nanorod array photodetectors. [ABSTRACT FROM PUBLISHER]

ZnO nanorod arrays are grown on Mg-doped GaN layer using the vapor cooling condensation system. To suppress the surface states and the dangling bonds residing on the sidewall surface of the ZnO nanorods, photoelectrochemical (PEC) surface passivation is carried out on the ZnO nanorods. The peak photoresponsivity of the unpassivated and the passivated ZnO nanorod photodetectors operating at -5~V was 3.0\times 10^3~A/W and 4.6\times 10^2~A/W, respectively. The PEC treatment dramatically reduces the noise equivalent power level and increased the specific detectivity up to a value of 1.43\times 10^15~cmHz^1/2~W^-1 Moreover, the noise power density spectra of the ZnO nanorod array photodetectors changed from the dependence of 1/f^2 to 1/f. These results demonstrate that the generation-recombination centers are successfully passivated by the PEC oxidation method. [ABSTRACT FROM PUBLISHER]