Semiconductor materials and methods of producing them

Abstract

A method of producing particles containing metal oxide for use in semiconductor devices includes the steps of heating metal-containing particles in a flame produced by a mixture of oxygen and a fuel component comprising at least one combustible gas selected from hydrogen and hydrocarbons, the oxygen being present in the mixture in a proportion of not less than 10 mole% below, and not more than 60 mole% above, a stoichiometric amount relative to the fuel component, so as to oxidize metal in at least an outer shell of the particles; cooling the oxidized particles by feeding them into a liquid or sublimable solid medium; collecting the cooled oxidized particles; and providing a distance between entry of the particles into the flame and collection of the particles of at least 300mm. In this manner, such particles may be oxidized so as to provide a shell of metal oxide material which leaving unoxidized a core of metal. A semiconductive layer of such particles on a substrate may be formed by feeding, to a hot zone, such preoxidized metal-containing particles; heating the metal-containing particles in the hot zone to render the particles at least partially molten; and depositing the particles in the at least partially molten state onto the substrate. The above oxidation process may be employed to provide metal oxide particles in which different respective metals having different respective valencies are present in different respective molar proportions. The valencies and molar proportions may be selected so as to provide n- or p-type semiconductor layers.

Description

technical field [0001] The present invention relates to semiconductor materials, in particular semiconductor materials made of metal oxides, especially transition metal oxides, and methods for the manufacture of these semiconductor materials. [0002] The invention also relates to devices for detecting radiation comprising ionizing radiation, electromagnetic radiation and nuclear radiation such as neutron radiation, in particular comprising radiation detecting semiconductor materials made of metal oxides. Background technique [0003] Conventional radiation detection devices include scintillation devices such as Geiger counters and ionization chambers. A diatomic gas is contained within a low pressure chamber, and the chamber has two junction areas to which a voltage is applied. [0004] The effect of the radiation causes the low pressure diatomic gas to dissociate / ionize, and the ions are attracted to the respective junction areas where they discharge. The discharge rate ...

AI Technical Summary

Problems solved by technology

Indeed, diodes are fragile and require encapsulation to protect them from atmospheric corrosion and mechanical damage

[0018] Also, they are expensive to manufacture and require complex and expensive production equipment utilizing highly toxic materials and 'clean room' conditions

It is extremely difficult to manufacture large-area diodes even with specialized equipment

[0019] Also, the electronic signals generated by Si and Ge diode devices are weak and require strong electronic amplification

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