β-Ga₂O₃ nanorod arrays with high light-to-electron conversion for solar-blind deep ultraviolet photodetection

Abstract

Vertically aligned β-Ga2O3 nanorod arrays with high light coupling and rapid electron transport were assembled for solar-blind deep UV detection.

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

“…These values are superior to lately reported results for β-Ga 2 O 3 MSM PD based on vertical nanorod arrays [17].…”

“…The inset of Figure 3B shows the peak responsivity of the β-Ga 2 O 3 nanowire PD as a function of the bias voltage. The responsivity of the β-Ga 2 O 3 nanowire PD increases approximately linearly with bias voltage, and the value of external quantum efficiency (EQE), which is calculated by EQE = hcR λ /(eλ) [17] is about 58% at the bias of 5 V. In addition, the detectivity (D * ) of the β-Ga 2 O 3 nanowire PD is estimated to be 4.4 × 10 11 Jones by the expression:…”

“…Recently, Ga 2 O 3 has gained added interest as a promising candidate for solar-blind photodetection because of its wide bandgap of 4.5-4.9 eV, good chemical and thermal stability [5][6][7][8]. Ga 2 O 3 -based solarblind PDs are mainly fabricated on β-Ga 2 O 3 with different forms, including single crystals [9,10], thin films [11,12], individual nanowire/nanowires [13,14] and nanowire arrays [15][16][17]. Among them, vertical nanowire arrays can exhibit obvious advantages in optical absorption and carrier generation due to high surface-to-volume ratio and effective light-trapping absorption, which will enable Ga 2 O 3 PDs with higher performance.…”

“…Among them, vertical nanowire arrays can exhibit obvious advantages in optical absorption and carrier generation due to high surface-to-volume ratio and effective light-trapping absorption, which will enable Ga 2 O 3 PDs with higher performance. At present, Ga 2 O 3 nanowire arrays are mostly obtained by the bottom-up epitaxy method [15,17,18]. Wang et al [17] have prepared β-Ga 2 O 3 nanowire arrays using hydrothermal and postannealing method, and the fabricated nanowire PD has a responsivity of 10.80 × 10 −3 A/W and a photoresponse time of 0.38 s. Chen et al [15] have grown β-Ga 2 O 3 nanowire arrays by a simple partial thermal oxidation process and fabricated the Schottky UV PD with a response time in the order of microseconds.…”

“…At present, Ga 2 O 3 nanowire arrays are mostly obtained by the bottom-up epitaxy method [15,17,18]. Wang et al [17] have prepared β-Ga 2 O 3 nanowire arrays using hydrothermal and postannealing method, and the fabricated nanowire PD has a responsivity of 10.80 × 10 −3 A/W and a photoresponse time of 0.38 s. Chen et al [15] have grown β-Ga 2 O 3 nanowire arrays by a simple partial thermal oxidation process and fabricated the Schottky UV PD with a response time in the order of microseconds. Latterly, Li et al [18] have reported the self-catalyzed metal organic chemical vapor deposition (MOCVD) growth of vertical Ga 2 O 3 nanowire arrays.…”