Abstract: A temperature sensor having a semiconductor body is disclosed. The semiconductor body includes a substrate of a compound semiconductor and an epitaxial layer of a mixed crystal in which different conduction band minima with different effective masses are energy-wise closely adjacent. A particular embodiment comprises the mixed crystal series gallium-aluminum-arsenic having the composition Ga.sub.1-x Al.sub.x As, in which the aluminum concentration is 0.2.ltoreq.x.ltoreq.0.43. The temperature sensor formed in this manner provides a simplified design and a wide linear temperature range. Additionally, the temperature range is extended without the need for a shunt resistance.

Abstract: A detector system for computer tomography or computer radiography contains a plurality of flat detectors which are arranged side by side in the plane of a fan-shaped beam of ionizing rays. According to the invention, detectors of high purity germanium are provided, whose volume is selected so that the contribution of the generation-recombination current to the shot noise of the detectors is substantially smaller than customary in detectors for ionizing rays. With these detectors one obtains a good local resolution as well as a good signal-to-noise ratio and one requires no vacuum and no cooling.

Abstract: A light-emitting diode comprises III-V semiconductor material having a pn junction as its light-active zone from which luminescent radiation is emitted, the radiation having a pressure-dependent characteristic. The diode is characterized in that, for the purpose of pressure-dependent brightness of the light radiation, the composition of the light-active zone at the pn junction comprises a semiconductor material which has a composition which corresponds to a position close to the transition from a direct energy gap to an indirect energy gap and at which a change of the composition would result in a significant change in the brightness of the emission. The invention is particularly useful for potential-free measurement of pressure forces.

Abstract: A pressure sensor having a semiconductor body is disclosed. The sensor comprises a substrate of a compound semiconductor and an epitaxial layer of a mixed crystal, in which different conduction band minima with different effective masses are closely adjacent energywise, particularly from the mixed crystal series gallium-aluminum-arsenic with the composition Ga.sub.1-x Al.sub.x As, in which the aluminum concentration is 0.19.ltoreq.x.ltoreq.0.43. The sensor described has a simplified design and predetermined pressure ranges can be set by varying the concentration of the crystal constituents.

Abstract: A method for improving the memory effect and brightness of an alternating current (AC) excited thin film electroluminensence (ACTEL) device is described. A typical ACTEL device has a thin luminescent layer made of ZnS thin film doped with Mn which is sandwiched between two dielectric layers. ACTEL devices exhibit a brightness versus voltage amplitude hysteresis loop which is commonly referred to as the memory effect. The application of a hybrid AC excitation waveform to the ACTEL device provides increased brightness and improved memory effect stability. The hybrid waveform has an initial portion that is sufficiently high for efficient carrier generation and a remaining waveform portion that is at a lower level than the initial portion for charge collection and holding purposes.