Ultra-wide bandgap semiconductor Ga₂O₃based electronic devices are expected to perform beyond wide bandgap counterparts GaN and SiC. However, the reported power figure-of-merit hardly can exceed, which is far below the projected Ga₂O₃material limit. Major obstacles are high breakdown voltage requires low doping material and PN junction termination, contradicting with low specific on-resistance and simultaneous achieving of n- and p-type doping, respectively. In this work, we demonstrate that Ga₂O₃heterojunction PN diodes can overcome above challenges. By implementing the holes injection in the Ga₂O₃, bipolar transport can induce conductivity modulation and low resistance in a low doping Ga₂O₃material. Therefore, breakdown voltage of 8.32 kV, specific on-resistance of 5.24 mΩ⋅cm², power figure-of-merit of 13.2 GW/cm², and turn-on voltage of 1.8 V are achieved. The power figure-of-merit value surpasses the 1-D unipolar limit of GaN and SiC. Those Ga₂O₃power diodes demonstrate their great potential for next-generation power electronics applications.

In this work, we report on demonstrating the firstvertical ${\rm{\beta}-Ga_{2}O_{3}}$ junction barrier Schottky (JBS) diode with theimplementation of thermally oxidized p-type NiO to compensatethe dilemma of the forfeit of the p-type ${\rm{\beta}-Ga_{2}O_{3}}$ . With this widebandgap p-type NiOx, ${\rm{\beta}-Ga_{2}O_{3}}$ JBS diodes with an area of 100×100 ${\mu m^{2}}$ achieves a breakdown voltage (BV) and specific onresistance(Ron,sp) of 1715 V and 3.45 ${m\Omega\cdot cm^{2}}$ , respectively,yielding a Baliga'figure of merit (FOM) of ${BV^{2}/R_{on,sp}= 0.85 \rm{GW/cm^{2}}}$ , which is the highest direct-current (DC) FOM valueamong all ${\rm{\beta}-Ga_{2}O_{3}}$ diodes. Meanwhile, a large size JBS diodewith area of 1×1 ${mm^{2}}$ shows a forward current (IF) and BV of 5A/700 V, which is also the best IF and BV combinations (FOM =64 MW/ ${cm^{2}}$ ) among all published results about large area Ga2O3diodes. Dynamic switching characteristics reveal that the diodesuffers from negligible current collapse phenomenon even at a -600 V and 103 s stress, showing the great promise ofimplementing p-NiO in the future ${\rm{\beta}-Ga_{2}O_{3}}$ power electronicdevices.

In this letter, we propose to implement a microwave lateral GaN Schottky barrier diode (SBD) in a designed 5.8-GHz rectifier circuit for future high-power and high-efficiency wireless power transfer. The low-pressure chemical vapor deposition SiN-passivated lateral GaN SBD demonstrates a low turn- on voltage of 0.38 V, a low on -resistance of 4.5 Ω, a low junction capacitance of 0.32 pF at 0-V bias, and a high breakdown voltage of 164 V, which are essentials for a high-efficiency and high-power rectifying application. By incorporating this lateral GaN SBD in a well-designed 5.8-GHz rectifier circuit, an unprecedented combination of high efficiency and high power is achieved simultaneously. The rectifier circuit demonstrates a high RF/dc conversion efficiency ( η _RF/DC ) of 71 ± 4.5% with an input power ( P _in ) of 2.5 W and η _RF/DC = 50 ± 4.5% with P _in = 6.4 W per single diode, showing the great promise of embracing lateral GaN SBD for future wireless high-power transfer application.

In this letter, we report on demonstrating high-performance lateral GaN Schottky barrier diode (SBD) on silicon substrate with low turn-on voltage ( $\text{V}_{\mathbf {on}}$ ), high breakdown voltage (BV) with low reverse leakage current ( $\text{I}_{\mathbf {R}}$ ), and high power figure of merit (P-FOM) through anode engineering technique. Lateral GaN SBD with anode-cathode distance ( $\text{L}_{\mathbf {AC}}$ ) of $25~\mu \text{m}$ demonstrates a $\text{V}_{\mathbf {on}} =0.38$ V, a BV of >3 kV at a $\text{I}_{\mathbf {R}}$ of $10\mu \text{A}$ /mm and differential specific ON-resistance ( $\text{R}_{\mathbf {on,sp}}$ ) of 2.94 $\text{m}\Omega ~\cdot $ cm ² , yielding a high P-FOM of more than 3 GW/cm ² . To the best of our knowledge, this P-FOM is the highest value among all the GaN SBDs on any substrates. Combining with 5 A forward current ( $\text{I}_{\mathbf {F}}$ ) and reverse BV >2 kV of a large periphery device with perimeter of 20 mm, GaN SBD with anode engineering technique shows its great promise for next generation power electronics.