| 摘要 |
Production of high resistivity semiconductor crystals of the type CdXTe, where X = Zn, Se, ZnSe, or nothing, involves multiple doping with Fe and at least one second element selected from Group III of the Periodic Table, especially Al and Ga. The multiple doping comprises double doping or co-doping. Preferably, the doping elements are of three different types. Preferred Features: The doping elements are combined with or introduced into the starting material for forming crystalline material, in amounts between parts per billion to parts per million. The relative amounts of Fe and the second element, expressed in atomic fractions, is 2.5:1 to 1.5:1, preferably 2:1. Growth and/or subsequent annealing of the crystals are/is carried out in the presence of H2 and/or N2 gas. Growth or pulling of the crystals is carried out by the Traveling Solvent Method, Bridgman methods or the High Pressure Bridgman Method, using a starting material having a slight excess of Te. In the High Pressure Bridgman Method, crystal growth is carried out at a neutral gas pressure of at most 50 bars, preferably 10-30 bars, more preferably around 15 bars. In the Bridgman method, the starting material is placed in a sealed quartz ampoule in a vacuum or at low neutral gas pressure. The doping elements are incorporated into a mixture of Cd and Te and optionally Zn and/or Se that form the starting material. The crucible containing the starting material, either in its entirety or partially comprises a material selected from quartz, pyrolytic carbon, vitreous graphite and boron nitride. Independent claims are given for: (a) a crystalline semiconductive material of formula Cd1-xXxTe, where x is between 0 and less than 1, and X = Zn and/or Se; (b) a radiation detector, particularly a nuclear radiation detector, comprising the crystalline semiconductive material; and (c) an opto-electronic device comprising the crystalline semiconductive material as an active element. |
