Memory switch

Instead of the original figure of Kies, we prefer the set-up shown in Fig. 3.63 (Fig. 3 in the paper on instrumentation), as it allows a more direct comparison with Fig. 3.57. For curve A the current density j = i/A was 1/3 of the maximum value at a recorder-paper velocity X = 10 s cm 1 with the memory switched off, for curve B j was 1/2.236 of the maximum value at a recorder-paper velocity X = 10 s cm"1 with the memory switched on, and for curve C j was 1/5.590 of the maximum value at a recorder-paper velocity X = 25scm-1 with the memory switched on. 

Lim SJ, Seo J, Park SY (2006) Photochromic switching of excited-state intramolecular proton-transfer (ESIPT) fluorescence a unique route to high-contrast memory switching and nondestructive readout. J Am Chem Soc 128 14542-14547... 

From a regulatory point of view, CaM kinase II is of particular interest as it has the characteristic of an enzyme with a built-in memory switch". The memory allows the CaM kinase to conserve a stimulatory signal over a longer period of time and to remain in an activated state, even when the initiating stimulus has died away. 

The great interest in this material stems from its applications in solar-energy conversion, thin-film transistors, memory switches, and electrophotography (204). 

Fig. 1. Current-voltage characteristics for (a) threshold switching and (b) memory switching.

The closest parallel to the a-Si devices described in this paper seems to be the observation of memory switching in heterojunctions of n-type ZnSe grown epitaxially on p-type (single-crystal) Ge substrates, reported by Hovel (1970) and by Hovel and Urgell (1971). The ZnSe-Ge heterojunction devices are polar and the transition times for the OFF-ON and ON-OFF operation are both in the region of 100 nsec or less. Similar, but not so... 

A-Si H memory switches do not have counterparts in standard crystalline semiconductor technology, unlike the sensors, TFTs and LEDs. However, amorphous semiconductor switching devices have a... 

Fig. 10.14. Current-voltage characteristics of the a-Si H memory switch, showing the reversible transition from a high resistance to a low resistance state (Owen et al. 1983).

Fig. 10.IS. The delay time for memory switching versus applied voltage, is the critical switching voltage (Owen et at. 1983).

Fig. 10.16. Dependence of the memory switch oif-resistance and on-resistance on device area, showing evidence of filamentary conduction in the on-state (LeComber et al. 1985).

F The free memory switch. Shows all the free memory blocks in the first 640KB and their starting addresses. Also useful in optimizing memory. 

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