Solar-blind ultraviolet photodetector based on vertically aligned single-crystalline β-Ga₂O₃ nanowire arrays

Abstract

Vertically aligned nanowire arrays, with high surface-to-volume ratio and efficient light-trapping absorption, have attracted much attention for photoelectric devices. In this paper, vertical β-Ga2O3 nanowire arrays with an average diameter/height of 110/450 nm have been fabricated by the inductively coupled plasma etching technique. Then a metal-semiconductor-metal structured solar-blind photodetector (PD) has been fabricated by depositing interdigital Ti/Au electrodes on the nanowire arrays. The fabricated β-Ga2O3 nanowire PD exhibits ∼10 times higher photocurrent and responsivity than the corresponding film PD. Moreover, it also possesses a high photocurrent to dark current ratio (Ilight/Idark) of ∼104 and a ultraviolet/visible rejection ratio (R260 nm/R400 nm) of 3.5 × 103 along with millisecond-level photoresponse times.

A Selective Etching Route for Large-Scale Fabrication of β-Ga2O3 Micro-/Nanotube Arrays

“…The vertically aligned GaN and β-Ga 2 O 3 NW arrays were successfully fabricated by ICP etching using self-assembled Ni nanoislands as the etching masks [23]. ICP power/RF power, chamber pressure, and Cl 2 /BCl 3 gas mixing ratio were adjusted to investigate the effect of input process parameters on the etch characteristics of GaN and β-Ga 2 O 3 films.…”

“…The etching behavior of Ga 2 O 3 is completely different from that of GaN, more similar to Al 2 O 3 [21]. Our group conducted a systematic study on the ICP etching characteristics of β-Ga 2 O 3 and the preparation process of β-Ga 2 O 3 NW structure, and successfully prepared GaN and β-Ga 2 O 3 NW arrays by ICP etching technology based on Cl-based plasma, respectively [22,23]. These studies indicate that Ga 2 O 3 requires relatively higher etching power and etching gas flow than GaN.…”

Orthoquinone–Based Covalent Organic Frameworks with Ordered Channel Structures for Ultrahigh Performance Aqueous Zinc–Organic Batteries

“…[32] As illustrated in Figure 3e, no obvious voltage drop spinodal is observed during the intermittent discharge-charge process. These flat curves indicate that there is no strict limit for cations' insertion, which is different from conventional inorganic materials, [33] and this will be studied in the following section. The calculated diffusion efficiency stabilizes at 10 À 8 -10 À 7 cm 2 s À 1 (Figure 3f, the detailed calculation process can be seen in Figure S18, S19 of the Supporting Information), where the magnitude of the diffusion coefficient is superior to most of the reported materials (Table S2).…”

Detached Vertical (Al,Ga)N Nanowires to Realize the Flexible Ultraviolet Photodetector with High Ultraviolet/Visible Reject Ratio and Detectivity

“…Compared with thin films, nanowires (NWs) have large surface‐to‐volume ratios, which can enhance optical absorption. [ 23,24 ] To obtain high flexibility and maintain high performance under strain and deformation, NWs represent an effective approach. [ 25,26 ] On the other hand, (Al,Ga)N has a series of excellent features, such as nontoxicity, long lifetime, and high stability against UV radiation.…”