Abstract: 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.

Abstract: 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.

Abstract: The invention relates to semiconducting nanoparticles. The nanoparticles of the invention comprise a single element or a compound of elements in one or more of groups II, III, IV, V, VI. The nanoparticles have a size in the range of 1 nm to 500 nm, and comprise from 0.1 to 20 atomic percent of oxygen or hydrogen. The nanoparticles are typically formed by comminution of bulk high purity silicon. One application of the nanoparticles is in the preparation of inks which can be used to define active layers or structures of semiconductor devices by simple printing methods.

Abstract: The invention relates to a method of doping semiconductor material. Essentially, the method comprises mixing a quantity of particulate semiconductor material with an ionic salt or a preparation of ionic salts. Preferably, the particulate semiconductor material comprises nanoparticles with a size in the range 1 nm to 100 ?m. Most preferably, the particle size is in the range from 50 nm to 500 nm. Preferred semiconductor materials are intrinsic and metallurgical grade silicon. The invention extends to a printable composition comprising the doped semiconductor material as well as a binder and a solvent. The invention also extends to a semiconductor device formed from layers of the printable composition having p and n type properties.