Search

Self‐powered solar‐blind photodiodes with convenient operation, easy fabrication, and weak‐light sensitivity, are highly desired in environmental monitoring and deep space exploration. Ga2O3 with its bandgap directly corresponding to solar‐blind waveband is a promising candidate material for solar‐blind photodetection. However, ever‐reported self‐powered Ga2O3 photodiodes suffer unsatisfactory photoresponse performance, owing to unideal interface and electrode transmittance. Here, Ag nanowire (AgNW) networks with excellent solar‐blind ultraviolet transmittance are introduced to form self‐powered AgNW–Ga2O3 photodiodes with sharp Schottky interfaces. The tradeoff between solar‐blind ultraviolet transmittance and carrier‐collection ability of the sparse AgNW network is systematically studied and the AgNW density is optimized for the best photoresponse. Expansion of depletion region outwards the AgNW–Ga2O3 contact and the field crowding effect facilitate the high photoresponse. As a result, the champion AgNW–Ga2O3 Schottky photodiode exhibits excellent sensitivity for weak‐light detection, including considerable responsivity of 14.8 mA W–1, ultrahigh photo‐to‐dark‐current ratio above 1.2 × 105, high rejection ratio (R254 nm/R365 nm) of 2.6 × 103, and fast response speed (rise/decay time of 20/24 ms) under self‐powered mode. Balancing the transmittance and carrier‐collection ability of elaborate electrode provides an alternative strategy to achieve high‐performance self‐powered Ga2O3 photodetectors for future weak‐light‐sensitive optoelectronic systems. [ABSTRACT FROM AUTHOR]

In this letter, trench-gate metal–oxide–semiconductor field-effect transistors on (010) $\beta $ -Ga2O3 epitaxial layer are fabricated. Enhancement mode is achieved by the gate-recess process, through thoroughly depleting the $\beta $ -Ga2O3 channel to get a positive threshold voltage. For the first time, by using a dynamic parameter test system, the Ga2O3 MOSFET with 2- $\mu \text{m}$ gate length is characterized to present short switching time, including turn-on time ($\textit {t}_{ \mathrm{\scriptscriptstyle ON}}$) of 28.6 ns and turn-off time ($\textit {t}_{ \mathrm{\scriptscriptstyle OFF}}$) of 94.0 ns. In addition, OFF-state interelectrode parasitic capacitances, including input capacitance ($\textit {C}_{\text {iss}}$) of 37 pF/mm, output capacitance ($\textit {C}_{\text {oss}}$) of 42 pF/mm, and reverse transfer capacitance ($\textit {C}_{\text {rss}}$) of 14 pF/mm are also obtained, which can account for the high switching speed. The static and dynamic switching properties of the trench-gate device show the potential of $\beta $ -Ga2O3 MOSFET for the high-speed switching applications. [ABSTRACT FROM AUTHOR]

In this letter, source-field-plated $\beta $ -Ga2O3 MOSFETs are fabricated on Si-doped homoepitaxial film on (010) Fe-doped semi-insulating $\beta $ -Ga2O3 substrate. Ohmic contact resistance (${R}_{\textsf {c}}$) between metal- and ion-implanted source/drain layer of $1.0~\Omega ~\cdot $ mm is obtained by employing the Si-ion implantation. The fabricated source-field-plated $\beta $ -Ga2O3 MOSFETs with source-to-drain distance (${L}_{\textsf {sd}}$) of 11 and $18~\mu \text{m}$ present high-saturation drain current (${I}_{\textsf {ds,sat}}$) of 267 and 222 mA/mm with low ${R}_{\textsf {on,sp}}$ of 4.57 and 11.7 $\text{m}\Omega ~\cdot $ cm2, respectively. The drain extension in the source-field plate effectively suppresses the peak electric field and improves the breakdown voltage greatly. The destructive breakdown voltages (${V}_{\textsf {br}}$) are measured to be 480 and 680 V for the devices with ${L}_{\textsf {sd}}$ of 11 and 18 $\mu \text{m}$ , respectively. Most of all, the power figure of merit (${V}_{\textsf {br}}^{\textsf {2}}/{R}_{\textsf {on,sp}})$ is as high as 50.4 MW/cm2, which is the highest value among any $\beta $ -Ga2O3 MOSFETs ever reported. [ABSTRACT FROM AUTHOR]