Charge-coupled devices operation characteristics

Optical spectroscopy ranging from Raman through Atomic is under considerable pressure to replace the "tried and true" photomultiplier tube (PMT) with multichannel devices. Two classes of solid state devices, the Charge Coupled Device (CCD) and the Charge Injection Device (CID), hold great promise for meeting this need. Operating modes of these devices are reviewed. Characteristics pertinent to analytical spectroscopy are presented. 

Here we attempt to relate the dynamic processes, measured by time correlation functions, to their characteristic timescales in the temperature range 300-600 K, relevant to organic electronic devices operation and fabrication. It is worth mentioning that in such applications, beyond the stmctiunl dynamics treated here, the timescales associated with charge or exciton dynamics are also very important, in particular for assessing the coupling between electron and nuclear dynamics. 

Such effects can be especially significant in many modem miniature electrochemical devices like sensors or batteries. For example, in a common Li battery, the spirally wound thin electrodes of metal foil are separated by an electrolyte layer of 10 cm order of thickness. The diffusion coefficient of Li in the electrode material is about 10 cm s the path of diffusion being of about 10 cm. Then the characteristic time is estimated as 10 s, that is, less than an hour. Since operation time of a battery (charge or discharge) is several hours, one can suspect that the coupling effects are important. Indeed, here we have the situation familiar to battery researchers— the behaviour of the electroactive materials in standard electrochemical cells with large volume of the electrolyte and in a real battery surrounding is often quite different. Thus, the reliable data oti the properties of electroactive battery materials can be obtained only in real batteries or mock-up cells with similar dimensions. That was established empirically and became a common research practice in the recent years. 

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