Superior high temperature performance of 8 kV NiO/Ga₂O₃vertical heterojunction rectifiers

Abstract

NiO/β-Ga2O3 vertical rectifiers exhibit near-temperature-independent breakdown voltages (VB) of >8 kV to 600K. For 100 µm diameter devices, the power figure of merit (VB)2/ RON, where RON is the on-state...

The transparent photovoltaic NiO/TiO2 orderly nanoarray pn junction via synergism of AgInS2 quantum dots and Ti3+ self-doping

“…This indicates the presence of Ni in the Ni 2+ /Ni 3+ mixed state, and is also an important factor for inducing a hole-related carrier. 11–14 Moreover, the peaks at 367.55 and 373.56 eV are from the Ag + ions (Fig. 2(l)), the peaks at 444.37 and 451.90 eV are from the In 3+ ions (Fig.…”

“…S4b, ESI†) are 3.749(NiO) and 3.204(TiO 2 ) eV. 12–14,22–24 With reduction, the band gaps of Ti 3+ -TiO 2 exhibit a continuous decrease to 2.893 (Ti 3+ TiO 2 -1), 2.853 (Ti 3+ TiO 2 -2), 2.842 (Ti 3+ TiO 2 -3) and 2.831 (Ti 3+ TiO 2 -4) eV. 37–39 Such appropriate band gaps would be the main reason for these NiO/Ti 3+ -TiO 2 pn junctions to maintain good transparency after introducing of Ti 3+ /O v .…”

“…11 In addition to the wide band gap guaranteeing good daylight and abundant nickel reserves making it low cost, the adjustable Ni 2+ /Ni 3+ state can efficiently induce hole-related carriers to advance the photovoltaic conversion efficiency upper limit. 12,13 Liu et al fabricated the Ga 2 O 3 /NiO/SiC triple pn junction to achieve a remarkable ultraviolet photoelectric response. 14 Cheng et al also improved the NiO-based solar cell via the SnO 2 electron transport layer.…”

15 MeV proton damage in NiO/β-Ga2O3vertical rectifiers

“…The vertical rectifiers have been described in detail previously [23][24][25], but in brief consist of 10 µm drift region of lightly n-type Ga 2 O 3 grown on a conducting n + Ga 2 O 3 . NiO with a total thickness of 20 nm is deposited on the top surface by sputtering and contacts made to both sides by e-beam evaporation of Ti/Au to the rear surface and Ni/Au to the NiO.…”

“…This has led to recent demonstrations of vertical rectifiers with breakdown voltages more than 8 kV with excellent high temperature operation [9]. While the device performance is promising in terms of dc and switching applications [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26], little is known about the effects of radiation on these heterojunctions. While the Ga 2 O 3 is known to be relatively resistant to total dose damage [27,28], large reversible changes in current-voltage characteristics of the heterojunctions have been observed after Co-60 gamma ray exposure which appears to be due to conductivity changes in the NiO [29].…”