Microwave Techniques in Measurement of Lifetime in Germanium

Ramsa, Alexander; Jacobs, H.; Brand, F.A.

doi:10.1063/1.1776978

Cited by 72 publications

(13 citation statements)

References 4 publications

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“…Time-resolved measurements of the excess electronhole recombination due to various recombination processes are particularly adept at detecting material defects in semiconductors and have resulted in the publication of over 300 papers, covering 35 different methods, in the following 15 years of work [6]. Non-contact measurements capable of accurately describing the behavior of carrier lifetime in semiconductors using the transmission of microwaves through a sample were first reported in 1959 [7]. Shortly afterwards, several articles reported the ability of a microwave reflectance techniques capable of accomplishing the same goals in 1962-1963 [8][9][10].…”

Section: Microwave Detected Lifetime Measurementsmentioning

confidence: 99%

Microwave Instrumentation and Sensing Techniques for Quantum Efficiency and Minority-Carrier Lifetime Measurements

Lu¹

2000

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A non-contact method characterizing the quantum efficiency of a solar cell using the microwave reflectance signature is presented in this thesis. Traditional solar cell quantum efficiency (QE) measurements are only possible near the completion of the fabrication process using contacts in direct physical connection with the metalized surface tabs to probe and extract charge carriers from the device. However, pressure within the solar metrology industry to report the spectral performance of the device earlier in the manufacturing process as part of the process control loop requires that a new non-contact method be developed. This thesis work contributes the development of a non-contact focused microwave reflectance technique capable of acquiring the full 365nm-1100nm spectrum in under 1 minute. Unlike many similar Time Resolved Microwave Conductivity (TRMC) and Microwave Photoconductivity Decay (µP CD) systems based on the open-ended waveguide technique, this measurement is developed to perform measurements in the far-field. As such, a different mechanism for understanding the problem is presented using the modulated scatterer concept from antenna theory. Using a combination of high dielectric sensor pads and negative-index of refraction microwave lenses, we are able to tune the far-field field probe size from 5mm-150mm allowing for high speed single point in-line measurements or high spatial sensitivity laboratory measurements. i This thesis work contributes the development of a non-contact quantum efficiency measurement technique using the far-field microwave reflectance sig

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Section: Microwave Detected Lifetime Measurementsmentioning

confidence: 99%

Microwave Instrumentation and Sensing Techniques for Quantum Efficiency and Minority-Carrier Lifetime Measurements

Lu¹

2000

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“…The non-invasive, contact-free analog to PCD is TMR, which records the time evolution of the microwave reflection from a sample following optical excitation, essentially probing a change in the sample’s radio frequency (RF) conductivity 4,5 . Compared with TRPL, TMR has the advantage of improved sensitivity; furthermore, as it is the photo-conductivity that is probed, the sample does not need to emit and there is no need for wavelength-tailored collection optics or a high-speed optical detector.…”

Section: Introductionmentioning

confidence: 99%

Measurement of carrier lifetime in micron-scaled materials using resonant microwave circuits

et al. 2019

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The measurement of minority carrier lifetimes is vital to determining the material quality and operational bandwidth of a broad range of optoelectronic devices. Typically, these measurements are made by recording the temporal decay of a carrier-concentration-dependent material property following pulsed optical excitation. Such approaches require some combination of efficient emission from the material under test, specialized collection optics, large sample areas, spatially uniform excitation, and/or the fabrication of ohmic contacts, depending on the technique used. In contrast, here we introduce a technique that provides electrical readout of minority carrier lifetimes using a passive microwave resonator circuit. We demonstrate >10 5 improvement in sensitivity, compared with traditional photoemission decay experiments and the ability to measure carrier dynamics in micron-scale volumes, much smaller than is possible with other techniques. The approach presented is applicable to a wide range of 2D, micro-, or nano-scaled materials, as well as weak emitters or non-radiative materials.

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“…Microwave measurements of excess-carrier lifetime were first made on germanium in 1959 by Ramsa et al [2]. The property was evaluated from the time variation of transmitted microwave power, ∆ P ( t ) , under pulsed injection, with the specimen oriented perpendicular to the waveguide axis.…”

Section: Introductionmentioning

confidence: 99%

Method for the Microwave Measurement of Carrier Lifetime in Lightly Doped Silicon Ingots

et al. 2005

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A further investigation is conducted into a new microwave method for evaluating bulk lifetime in silicon ingots [1]. It is shown that for lightly doped ingots transmission and reflection microwave measurements yield different values of the decay time of photogenerated excess-carrier density. The discrepancy is attributed to the influence of surface recombination. Measurements are compared with theoretical predictions for a semiinfinite semiconductor specimen. Data are presented on bulk lifetimes in ten high-quality silicon ingots grown by the float-zone process and doped with phosphorus by neutron transmutation doping. The lifetimes are measured by microwave transmission or reflection and by probe injection.

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Microwave Techniques in Measurement of Lifetime in Germanium

Cited by 72 publications

References 4 publications

Microwave Instrumentation and Sensing Techniques for Quantum Efficiency and Minority-Carrier Lifetime Measurements

Microwave Instrumentation and Sensing Techniques for Quantum Efficiency and Minority-Carrier Lifetime Measurements

Measurement of carrier lifetime in micron-scaled materials using resonant microwave circuits

Method for the Microwave Measurement of Carrier Lifetime in Lightly Doped Silicon Ingots

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