The study of humidity sensor based on Li-doped ZnO nanorods by hydrothermal method

Economic Friendly ZnO-Based UV Sensors Using Hydrothermal Growth: A Review

“…Over decades, the hydrothermal technique has proven beneficial for the synthesis of ZnO nanostructures on either rigid or flexible substrates. Rigid substrates are often concerned about glass [ 2 , 22 , 33 , 44 , 48 , 59 , 61 ], whereas flexible substrates include silicon [ 45 , 100 ], polyimide (PI) [ 44 , 45 , 48 , 100 ], PET [ 19 , 34 , 68 ], polycarbonate (PC) [ 48 , 100 ], Kapton [ 101 ], PDMS [ 17 ], carbon fiber [ 17 , 29 ] and paper [ 17 ].…”

“…For the hydrothermal growth of ZnO pyroelectric nanowires, Dong et al prepared a mixture of 0.02 mM HMTA and 0.02 mM zinc nitrate [ 60 ]. Before nanowire growth, they deposited a 100 nm thick layer of ZnO seed on the p-Si substrate by the radio-frequency magnetron sputtering technique [ 19 , 21 , 59 ]. The as-grown nanowires were uniform with diameters of 40–70 nm and lengths of approximatively 2 µm.…”

“…Doping and loading of donor elements into ZnO structures have been widely studied to improve the stability, photoelectrical and optical properties of ZnO nanostructures [ 12 , 17 , 19 , 28 , 40 , 59 , 99 ]. Tsay et al showed that the co-doping of Ga and In ions into ZnO crystal significantly improved the photoelectrical properties and increased the p-n heterojunction UV PDs’ stability more than single doping of Ga or In [ 110 ].…”

“…Vapor-phase synthesis is generally carried out at high temperatures (from 500 to 2000 °C). Vapor-solid growth [ 48 ], vapor-liquid-solid growth (VLS) [ 18 , 48 , 54 ], chemical vapor deposition (CVD) [ 17 , 18 , 20 , 55 , 56 , 57 ], metalorganic vapor-phase epitaxy (MOVPE) [ 17 , 58 ], atomic layer deposition (ALD) [ 13 ] and sputtering [ 19 , 59 , 60 ] are examples of vapor-phase synthesis. Figure 1 shows the different synthesis methods of ZnO nanostructures.…”