A NEW MATERIAL FOR OPTICAL, ELECTRICAL AND ELECTRONIC THIN-FILM MEMORIES

A new category of erasable information storage media, M1-beta, (TCNQ) films, is described. The photochromatic effect of this organometallic charge-transfer complex can give high-contrast patterns produced directly on a fine-grain film by pulsed photon beams generated from a gas or semiconductor laser. The patterns are erasable. For a radiation with 632.8 nm, the number of write-erase cycles N > 1000 has been obtained with a coefficient of contrast K > 50%. Moreover, the non-linear I-V characteristics of the fine-grain M1-beta (TCNQ) film can be used as a bistable electric switching. An organometallic memory (OMM) with a storage density of 1 Mb CM-2 can be proposed and is compatible with silicon IC chips. To avoid the decoder, an electron-beam operated 'erasable access storage tube (EAST)' with a multi-layered M1-beta (TCNQ) target was designed. Its storage density can approach that of a laser disc and the access time is as short as a semiconductor memory. Since no single crystal or p-n junction is needed, the technology is relatively simple and a lower price per bit of memory can be expected.