Process for preparing thin films of crystalline metals or semiconductors on amorphous substrates, and thin-film electroluminescent device obtainable by means of such a process

摘要

A thin-film electroluminescent device, endowed with good electro-optical characteristics and with a threshold voltage for electroluminescence generally lower than 100 V, comprises:(a) an amorphous support;      on which there are deposited, in succession:(b) a metal layer;(c) a luminescent layer;(d) an insulating layer; and(e) a conductor layer; - with said (b) metal layer being a homogeneous layer of a binary alloy of two different metals, with a multicrystal structure, with columnar (tabular) grains with side dimensions equal to, or larger than, 1 µm, and with a thickness equal to, or higher than, 0.2 µm;- said (c) luminescent layer being a zinc sulphide or zinc selenide layer, doped with manganese metal, with manganese sulphide, or with another manganese salt, with a multicrystal structure, with columnar (tabular) grains with side dimensions equal to, or larger than, 1 µm, and with a thickness equal to, or lower than, 2 µm.;Said device is manufactured by means of a process which comprises:- the deposition, on an amorphous support of a layer of a first metal, in order to form a metal layer having an either amorphous or microcrystalline structure;- the deposition on the first metal layer of a second metal, melting at a lower temperature than the first metal, by operating under temperature conditions within which the first metal gradually melts in the form of a liquid alloy with the second metal, and crystallizes in the form of a binary and homogeneous solid alloy, in order to form a metal layer having a multicrystal structure;- the deposition, on the so-formed multicrystal metal layer, of the luminescent layer, and its epitaxial or quasi-rheotaxial growth, in order to form a multicrystal luminescent layer;- the finishing of the device by means of the deposition, in succession, of an insulating layer, and of a transparent conductive layer.