The present invention provides stretchable, and optionally printable, semiconductors and electronic circuits capable of providing good performance when stretched, compressed, flexed or otherwise deformed. Stretchable semiconductors and electronic circuits of the present invention preferred for some applications are flexible, in addition to being stretchable, and thus are capable of significant elongation, flexing, bending or other deformation along one or more axes. Further, stretchable semiconductors and electronic circuits of the present invention may be adapted to a wide range of device configurations to provide fully flexible electronic and optoelectronic devices.

The present application provides (in addition to more broadly applicable inventions) improvements which are particularly applicable to two-sided power semiconductor devices which use bipolar conduction. In this class of devices, the inventor has realized that two or three of the four (or more) semiconductor doping components which form the carrier-emission structures and control structures in the active device (array) portion of a two-sided power device can also be used, with surprising advantages, to form field-limiting rings around the active arrays on both surfaces. Most preferably, in some but not necessarily all embodiments, a shallow implant of one conductivity type is used to counterdope the surface of a well having the other conductivity type. This shallow implant, singly or in combination with another shallow implant of the same conductivity type, works to shield the well from the effects of excess charge at or above the surface of the semiconductor material.

An electronic device and a method of fabricating an electronic device are disclosed. The device includes a body of semiconductor material, and a conductive material defining at least three conducting contacts to form respective terminals. The semiconductor material and the conducting contacts overlap at least partially to define the device, so that the electrical characteristics of the device between any pair of terminals correspond to those of a varistor. The body of semiconductor material may be a layer deposited by printing or coating. The varistor characteristics between each pair of terminals enable switching of an electrical current between one terminal and any two other terminals in such a manner that when there is a positive current into a first terminal, there is a negligible current through a second terminal at which a positive potential is applied and a positive current out of a third terminal which is held at a negative potential with respect to the second terminal. When there is a negative current outwards of the first terminal, there is a positive current into the second terminal and a negligible current through the third terminal.

An embodiment relates to a light-emitting element, a method for producing same, a light-emitting element package, and a lighting system. A light-emitting element according to the embodiment may comprise: a first conductive semiconductor layer (112); a second conductive semiconductor layer (116) disposed below the first conductive semiconductor layer (112); an active layer (114) disposed between the first conductive semiconductor layer (112) and the second conductive semiconductor layer (116); a plurality of holes (H) exposing parts of the first conductive semiconductor layer (112) to the bottom surface of the second conductive semiconductor layer (116) by penetrating the second conductive semiconductor layer (116) and the active layer (114); first contact electrodes (160) electrically connected to the first conductive semiconductor layer (112) from the bottom surface of the second conductive semiconductor layer (116) through the plurality of holes (H); an insulation layer (140) disposed between the first contact electrode (160) and the plurality of holes (H); a bonding layer (156) electrically connected to the first contact electrodes (160); a support member (158) disposed below the bonding layer (156); a second contact electrode (132) electrically connected to the second conductive semiconductor layer (116); and a first current-spreading semiconductor layer (191) inside the first conductive semiconductor layer (112) above the first contact electrode (160).