US 4,536,679 A · Photocathode

Abstract

The photocathode is of the type which comprises a photo-emissive layer consisting of at least an active layer of the P-type, a solid support for said semiconductor of a material which is transparent to radiation, a layer having a bonding glass for the photo-emissive layer on the support. The invention is characterized in that the support comprises two parts situated one on top of the other and which are bonded together, namely a thick second part (thickness for example 5 mm) of a type of glass having properties of thermal expansion which are substantially identical to those of the bonding glass and a part in the form of a disk-shaped first part (thickness for example 1 mm) of a material having softening and transition points which are much higher than those of the bonding glass and of the glass of the thick part.

Claims2

Dependent claims

A photocathode comprising a transparent support bonded by a glass bonding layer to a semiconductor structure comprising a chemical passivating layer on an optical adaptation layer on an electrical passivating layer on a photoemissive layer, the transparent support acting as the window of a tube envelope, wherein the improvement comprises the support being in two parts bonded together as follows:

a first part connected to the glass bonding layer and thereby to the chemical passivating layer of the semiconductor structure, this first part comprising a glass having softening and transition temperatures which are higher than those of the glass bonding layer, and
a second part for connection to the tube envelope, said second part comprising a glass having softening and transition temperatures and properties of thermal expansion substantially equal to those of the glass bonding layer.

Dependencies are inferred from the claim text.

Photocathode

Life of this patent

Photocathode

Life of this patent

Abstract

Claims2