Abstract: A light emitting device that comprises an organic LED array containing a plurality of light emitting pixels, the pixels each being located on a common electrically insulative transparent substrate, is characterized in that the transparent support is ultra thin, having a thickness less than the pitch of the pixels. The pixels in the LED array can be arranged in intersecting columns and rows, or they can comprise a line array.
Abstract: An avalanche photodiode includes a multiplication layer and a photoabsorption layer, and the multiplication layer is formed of a semiconductor superlattice structure composed of a number of well layers each of which is formed of a short period superlattice of at least two kinds of semiconductors and which can be equivalently regarded to be a mixed crystal of the at least two kinds of semiconductors. In the short period superlattice, the mini-bands are formed within the superlattice well layers having its effective forbidden band width, which is larger than the forbidden band width in a bulk condition of a semiconductor layer constituting a well in the short period superlattice. Thus, the dark current due to the inter-band tunnel transition within the same well layer is decreased. Therefore, a low noise characteristics and a low noise and high response speed characteristics obtained by a high ionization rate ration can be simultaneously realized.
Abstract: A semiconductor device having active parts made from semiconductor diamond. The active parts include a high doped diamond layer for supplying free carriers and a non- or low doped diamond layer for giving the free carriers a conductive region. The free carriers are transferred from the high doped diamond layer to the non- or low doped diamond layer by diffusion or an applied electric field. Since the free carriers move at high speeds in the non- or low doped diamond layer without being scattered by dopant atoms, the semiconductor device is applicable to high frequency devices with stability against a change in temperature.
Abstract: The present invention is directed to novel optoelectronic devices, such as light emitters and detectors, that have a unique combination of semiconductor materials that provides a band arrangement resulting in improved efficiency of carrier injection. The devices are quantum well type devices in which discrete electronic states are formed by size quantization effects in the quantum well region. Electromagnetic radiation of emission and absorption occurs by the transition of electrons from a first energy state to a second energy state in either the conduction band or the valence band of the quantum well layer. The bands edges of the layers are offset such that under an appropriate bias, the discrete energy states reside in the bandgap of one of the electrodes and in an allowed region of the other electrode, with one state residing in the conduction band of one electrode and the other state residing in the valence band of the other electrode.
December 20, 1989
Date of Patent:
January 7, 1992
International Business Machines Corporation
Leo Esaki, Hideo Ohno, Emilio E. Mendez