Time-resolved microwave

Time-resolved microwave conductivity measurements with electrodes in electrochemical cells can conveniently be made with pulsed lasers (e.g., an Nd-YAG laser) using either normal or frequency-doubled radiation. Instead of a lock-in amplifier, a transient recorder is used to detect the pulse-induced microwave reflection. While transient microwave experiments with semiconducting crystals or powders have been performed... 

The texture of the catalysts also controls the half-lifetime of charge carriers. This can be easily obtained from microwave absorption experiments using a time-resolved microwave conductivity... 

Warman JM, de Haas MP, Dicker G, Grozema FC, Ptris J, Debije MG (2004) Charge mobilities in organic semiconducting materials determined by pulse-radiolysis time-resolved microwave conductivity 7c-bond-conjugated polymers versus tc—tc-stacked discotics. Chem Mater 16 4600... 

Salafsky et a/.435 showed time-resolved microwave conductivity measurements of the decay of electrons in Ti02 nanocrystals, following dye-sensitization. The time scale for this decay process is on the order of 100 msec to sec and explains the high electron collection efficiency r) in DSC, since the long time scale allows for slow transport through the Ti02 network. 

Martin ST, Herrmann H, Choi W, Hoffmann MR. Time-resolved microwave... 

Warman JM, de Haas MP, Pichat P, Koster TPM, Van der Zouwen-Assink EA, Mackor A, Cooper R. Electronic processes in semiconductor materials studied by nanosecond time-resolved microwave conductivity A1203, MgO and Ti02 powders. Radiat Phys Chem 1991 37 433-442. 

TC/BG BC/BG SC/BG BC/TG PR-TRMC Top contact/bottom gate Bottom contact/bottom gate Sandwich contact/bottom gate Bottom contact/top gate Pulse-radiolysis time-resolved microwave conductivity technique... 

Measured with the pulse-radiolysis time-resolved microwave conductivity (PR-TRMC) technique... 

State of Tetraphenylethylene Detected by Time-Resolved Microwave Conductivity. J. Am. Chem. SOC (1993) 115 3286-3290. 

The seminal work of Marcus and Hush has had a significant impact on the development of PET. Pioneering efforts by Sutin, Hopfield, Jortner, and others established the connection between thermal electron transfer and photoelectron transfer [6]. This work set the stage for a notable series of experiments where laser flash spectroscopy [7], chemically induced nuclear polarization [8], resonance Raman spectroscopy [9], time-resolved microwave conductivity [10], and time-resolved photoacoustic calorimetry [11], to site only a few examples, have been successfully employed to chart the dynamics of PET in homogeneous solution, the solid-state, and organized assemblies. 

Time-resolved microwave conductivity TRMC) Technique allowing the quantitative and qualitative detection of radiation-induced charge separation by time-re-solved measurement of the changes in microwave absorption resulting from the production and decay of charged and dipolar molecular entities. 

A History of Pulse-Radiolysis Time-Resolved Microwave Conductivity (PR-TRMC) Studies... 

A separate development of the TRMC techniques was their application to the study of dipolar and excitonic species formed on flash-photolysis of dilute solutions and, more recently, to charge transport and charge separation in thin (aligned) solid films. In the present review we restrict ourselves to results that we have obtained on pulse-irradiated materials, for which the method has become known as the pulse-radiolysis time-resolved microwave conductivity or PR-TBAIC technique. 

Warman JM, Gelinck GH, de Haas MP. (2002) The mobility and relaxation kinetics of charge carriers in molecular materials studied by means of pulse-radiolysis time-resolved microwave conductivity Dialkoxy-substituted phenylene-vinylene polymers. J Phys Condensed Matter 14 9935-9954. 

Warman JM, Cooper R. (1990) Electron thermalization and attachment in pulse-irradiated oxygen studied by time-resolved microwave conductivity. Radiat Phys Chem 36 517-521. 

Warman JM, de Haas MP, Pichat P, Serpone N. (1991) Effect of isopropyl alcohol on the surface localization and recombination of conduction-band electrons in Degussa P25 TiOj. A pulse-radiolysis time-resolved microwave conductivity study. JPhys Chem 95 8858-8861. 

Hoofman RJOM, van der Laan GP, de Haas MP, Tanigaki K. (1997) Charge migration in pulse-irradiated undoped C60 powder studied with the time-resolved microwave conductivity technique. Synth Met 86 2355-2356. 

Frey H, Moller M, de Haas MP, Zenden NJP, Schouten PG, van der Laan GP, Warman JM. (1993) Radiation-induced conductivity in poly(methylphenylsily-lene) and poly(di- -hexylsilylene) studied by time-resolved microwave conductivity. Macromol26 89-93. 

---