Bipolar junction device, and methods and switch assemblies using same. At least one example is a bipolar junction device that includes a substrate defining a first side and a second side, and a field-effect structure defined on the first side. The field-effect structure includes a channel region, a gate region in operational relationship to the channel region, and electrically insulated from the channel region, and a cathode region forming a junction with the channel region. A bipolar junction structure defined on the second side includes an injection region forming a junction with the substrate and an anode region in operational relationship to the substrate.

An insulated gate turn-off (IGTO) device, formed as a die, has a layered structure including a p+ layer (e.g., a substrate), an n epi layer, a p-well, an n-layer over the p-well, p+ regions over the n-layer, trenched gate regions formed in the p-well, and n+ regions between the gate regions, so that vertical npn and pnp transistors are formed. The device is formed of a matrix of cells. To turn the device on, a positive voltage is applied to the gate, referenced to the cathode. The cells contain a vertical p-channel MOSFET, for shorting the base of the npn transistor to its emitter, to turn the npn transistor off when the p-channel MOSFET is turned on by a slight negative voltage applied to the gate. One or more p-layers are implanted into the p-well, below the n-layer, for independently controlling the turn-on and turn-off threshold voltages and the breakdown voltage.

The disclosure provides dyes for marking hydrocarbon compositions. More particularly, the disclosure relates to non-mutagenic dyes for marking hydrocarbon compositions.