A smart junction box for photovoltaic systems provides electrical measurements of strings of photovoltaic cells to detect premature photovoltaic cell degradation, bypass diode failure, and arcing, and report the same to a central location and/or to provide for automatic disconnection of a given string of photovoltaic cells. The smart junction box also provides general reporting of electrical characteristics to the central system and allows disconnection by command from the central system.

To provide a semiconductor device capable of improving a discharge starting voltage when measuring electric characteristics, and widening a pad area of a surface electrode or increasing the number of semiconductor devices (number of chips) to be obtained from one wafer, and a method for manufacturing the same. A semiconductor device includes an n-type SiC layer having a first surface, a second surface, and end faces, a p-type voltage relaxing layer formed in the SiC layer so as to be exposed to the end portion of the first surface of the SiC layer, an insulating layer formed on the SiC layer so as to cover the voltage relaxing layer, and an anode electrode that is connected to the first surface of the SiC layer through the insulating layer and has a pad area selectively exposed.

A photovoltaic system, a power supply system, and an insulation fault detection method. An insulation impedance detection circuit is connected between a bus and the ground. The bus includes the direct current positive bus, the neutral bus, or the direct current negative bus. The insulation impedance detection circuit includes at least a switch. The direct current negative bus is connected to the neutral bus by using an electrical element or a voltage source. A controller obtains insulation impedance based on voltages to ground of the bus that are separately corresponding to the switch before and after the switch is turned on, and determines, based on the insulation impedance, whether there is an insulation fault in the photovoltaic system, to perform protection in a timely manner.

A method of estimating a breakdown voltage of a silicon dioxide film includes; generating breakdown voltage information associated with first test dies selected from among test dies, generating a breakdown voltage estimation model by updating a parameter of a neural network model based on the breakdown voltage information, applying test voltages to second test die selected from among the test dies and distinct from the first dies and receiving currents levels for current generated by the second test dies in response to the test voltages, wherein the test voltages have respective levels lower than levels of breakdown voltages for the first test dies, and estimating breakdown voltages of the second test dies using the breakdown voltage estimation model in relation to the currents levels.

A power device threshold voltage measurement circuit and its operation method thereof are provided. The measurement circuit includes a switch component, a device under test, a common source capacitor and a decoupling capacitor. The switch component and the device under test forms a half bridge circuit and the common source capacitor is in series connected at the source of the device under test. The device under test is connected as a lower switch of the half bridge circuit and the decoupling capacitor is connected between the device under test and the common source capacitor. By applying an OFF-state stress mode and a measurement mode successively afterwards, a threshold voltage of the device under test is obtained. And the present invention is beneficial to achieving in shorter pulse width, faster measuring speed and inexpensive measuring equipment, and can thus be widely applied to group III-N based power devices.

An electromagnetic wave detector includes a semiconductor layer, a two-dimensional material layer, a first electrode portion, a second electrode portion, and a ferroelectric layer. Two-dimensional material layer is electrically connected to semiconductor layer. First electrode portion is electrically connected to two-dimensional material layer. Second electrode portion is electrically connected to two-dimensional material layer with semiconductor layer interposed therebetween. Ferroelectric layer is electrically connected to at least any one of first electrode portion, second electrode portion and semiconductor layer. Electromagnetic wave detector is configured such that an electric field generated from ferroelectric layer is shielded with respect to two-dimensional material layer. Alternatively, ferroelectric layer is arranged so as not to be overlapped with two-dimensional material layer in plan view.