Novel Ga-ZnO Nanosheet Structures Applied in Ultraviolet Photodetectors

Abstract

Vertically aligned Ga-doped ZnO (GZO) nanosheets were grown on a glass substrate using a low-temperature (90 • C) hydrothermal method. The average length and diameter of the nanosheets were ∼720 and 26 nm, respectively. The GZO nanosheets exhibited wurtzite and monoclinic structures. A metal-semiconductor-metal ultraviolet (UV) photodetector (PD) was also fabricated for the GZO nanosheets. Results revealed that the photoresponses of the GZO UV PD were flat at short wavelengths. Meanwhile, a sharp cutoff was observed at 340 nm. The UV-to-visible rejection ratio of the fabricated PD was ∼89 at 1 V bias voltage.

Bandgap Engineered Ultraviolet Photodetectors with Gallium-Zinc-Oxide via Co-Sputtering Method

“…Previously, Yang et al proposed the fabrication of GZO nanosheet UV PDs using hydrothermal method. 36 The I Photo /I Dark ratio, responsivity at the cutoff wavelength, and UV-to-visible rejection ratio for their devices were 1.5 × 10 1 , 2.8 × 10 −5 , and 8.9 × 10 1 , respectively. On the other hand, previously reported GZO nanorod UV PDs exhibited an I Photo /I Dark ratio, responsivity at the cutoff wavelength, and UV-to-visible rejection ratio of 1.2 × 10 1 , 3 × 10 −2 , and 3.3 × 10 1 , respectively.…”

“…40 During the GZO co-sputtering procedure, under the same power of the Ga 2 O 3 target, increasing the power of the ZnO target may cause a high proportion of defect-induced traps in the GZO thin film for device C. 40 Hence, we can obtain longer rise/decay times from device C. As shown in Table II, the rise/decay times of the nanosheet GZO UV PDs are 46 and 32 s, respectively. 36 The rise/decay times extracted from nanorod GZO UV PDs are 29.75 and 89.67 s, respectively. 37 Nano-pagodas GZO UV PDs exhibited rise/decay times of 0.53 and 14 s, respectively.…”

Synthesis and characterization of ZnO flower-like structures

“…[1][2][3][4][5][6][7][8][9] In addition to one-dimensional ZnO structures, several types of morphologies, such as flowers, needles, hollow and solid rods [8][9][10][11] are of interest for their high surface to volume ratio, nanometer order thickness, excellent permeation, and optical properties make it suitable for devices applications. [2,12] A lot of attention has been paid over the past few years to the synthesis techniques of this material using different methods. ZnO nanorods and flowers are the promising materials for various types of sensor applications due to their ultrahigh surface-to-volume ratios.…”