| 摘要 |
1,186,075. Granular electrical devices PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES'Ltd. 11 April, 1967 [14 April, 1966], No. 16563/67. Heading H1K. Grains 13, e.g. of chalcogerides of Cd, Zn or Pb, are applied to a support together with a liquid filler, and the filler is hardened and allowed or caused to retract between the grains so that parts 19 of the grains are free of the filler. Suitable filler materials include paraffin, polyurethane, fusible solid esters of saturated fatty acids, or thermoplastic materials, e.g. polyamides such as nylon. Hardening may be effected by application of heat or cold, by polymerization or polycondensation, under the action of gaseous reactants such as O 2 , or by evaporation of a solution. A photo-resistor such as that described in Specification 1,186,074 can be made according to the invention, indium electrodes 18, 21 being vapour deposited on opposite sides of the device. Alternatively, Cu electrodes may be applied to form a photo-voltaic cell. In one embodiment, grains having a core (43), Fig. 11 (not shown), and an outer coating (44) of different electrical properties are embedded in an insulating filler, and part of the coating (44) is removed by etching to reveal a section (46) of the core, thereby permitting an electrode to be applied to the bore. In this case a second layer (47) of insulating filler material may be applied to the surface after etching, so as to prevent the subsequently applied electrode from contacting the coating (44). The coating and core may be of the same or different semi-conductor material, different dopings being used in the former case, or alternatively one of them may comprise a metal. Other types of device to which the invention is applicable include photo-cells, temperature-sensitive or non-linear resistors bolometers, diodes, or xerographic plates.
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