Photo conductors

A conversion treatment comprising electrolytical anodising of portions of a surface of an HgCdTe body is used in GB-A-1600S99 to form imagers having photo-conductors or photodiodes as detector elements. 

A plurality of photo-conductors 10 of HgCdTe form a focal plane array. Each photoconductor comprises a photon collection aperture 12, a confinement region 14 and an overlap metal layer 32. The metal layer 32 forms a common electrode on one side of the aperture and an individual electrode on the other side of the aperture. 

Many of the known atylamine containing polymers are potentially useful photo-conductors. It is unfortunate that a direct comparison of most of these polymers with PVK is not yet possible. Eadi author used a different method of evaluation and the results are not comparable. 

Typically, the resistance of a photocondticiive cell is inversely proportional to the radiant power / of the radiation striking it. If K and R., are matched photo conductors. 

Photoresistors, photodiodes, photo transistors, photo conductors, etc. Charge-coupled diode Measure light intensity with high sensitivity Inexpensive, reliable, and noncontact sensor Captures digital image of a field of vision... 

In photo-conductors, the gap between the valence and conduction bands is small enough that electrons can be excited into the conduction band by absorption of a visible photon. Some polymers, such as polyacetylene, and covalent crystals, such as graphite, may also have accessible conduction bands if they have partly filled rr-bond systems. Graphite has a much lower electrical and thermal conductance along the axis perpendicular to the plane of the sheets in this direction the atoms are connected only by the weak van der Waals forces. 

The need for cooling photo conductor detectors is a known necessity. However, the existing methods used for cooling can be improved through the use of cryogenic equipment. It is possible for the reliability of systems using the expansion of gas for cooling to be improved 90 per cent by the use of liquefied gas as the supply medium. 

The sample is placed on the insulating substrate. Two conducting strip-like electrodes are evaporated on the photo-conductor with the gap in the order of a few micrometers (Figure 19). The opposite side of the insulator is covered... 

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