The application of microwave cavity perturbation technique for the study of transients in semiconductors is becoming popular due to its simplicity in measurement procedure and high sensitivity. The paper discusses the effects of quality factor, sample size, and coupling factor on the sensitivity of the measurement. Also, it deals with a measurement approach for the study of triplet state transitions and excited state studies in organic solvents. Finally, a comparison between the cavity perturbation technique and the currently used reflection technique is made. © 1998 American Institute of Physics.

Venkatachalam Subramanian

Department Of Physics

Vemuri Rama Krishna Murthy

Jandhyala Sobhanadri

Fulltext

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IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Sensitivity analysis of transient measurements using the microwave cavity perturbation technique

Journal of Applied Physics

Composite fibers of single walled carbon nanotubes dispersed in poly(methyl methacrylate) and polystyrene are prepared using electrospinning. The single fiber electrical conductivity is measured as a function of the composition of carbon nanotubes. A noncontact method of measuring the carrier mobility at microwave frequency (14 GHz) using bimodal cavity is employed. The mobility measurements indicate lower percolation threshold for mobility compared to electrical conduction. For higher concentrations of carbon nanotubes, the mobility is found to decrease indicating possible carrier-lattice scattering. © 2008 American Institute of Physics.

Applied Physics Letters

Microwave Hall mobility studies on polymer-single walled carbon nanotube composite fibers

The transient nature of optical absorbance and the microwave cavity perturbation technique are used to measure the minority carrier lifetime in a polycrystalline thin film of Zn3P2 as well as to observe the spectral photoabsorbance. It has been observed that the transient decay curves consist of two components attributed to the surface carriers and the bulk carriers. The analysis of these spectral variation of carrier lifetime and spectral photoabsorbance indicate the possible band-band transitions in this material. © 1995.

Thin Solid Films

Minority carrier lifetime in thin films of Zn3P2 using microwave and optical transient measurements

The cavity perturbation technique is employed for the characterisation of semiconductors at microwave frequency for its conductivity. Temperature variation of microwave conductivity studies provide the information regarding the band gap, scattering parameter and impurity ionization energy. Change in the real part of the dielectric permittivity with conductivity indicates the change in the momentum relaxation time. © 1995 the Indian Academy of Sciences.

Pramana

Microwave conductivity studies on some semiconductors

A new approach of measuring the quality factor of the reflection type microwave cavity resonator for calculating the complex dielectric permittivity of solid and liquid samples in the cavity perturbation technique is proposed. This approach, based on the measurement of reflected power from the cavity at resonance, effectively reduces the measurement procedure and increases the accuracy. As the quality factor can be measured very fast using this approach, this approach can be extended to monitor the conductivity decay of the semiconductor samples.

Review of Scientific Instruments

New approach of measuring the Q factor of a microwave cavity using the cavity perturbation technique

To derive the expression for complex dielectric and magnetic susceptibilities, an easy and alternate approach is proposed. This analysis is based on the assumption that the cavity is equivalent to an isolated lumped resonant circuit. The results are identical with standard expressions. Results of a few samples are also tabulated. © 1989.

Journal	Data powered by TypesetJournal of Applied Physics
Publisher	Data powered by TypesetAmerican Institute of Physics Inc.
ISSN	00218979
Open Access	No