Modeling and analysis of photomodulated reflectance and double crystal x-ray diffraction measurements of tensilely strained InGaAs/InGaAsP quantum well structures

Rowland, G.; Hosea, T. J. C.

doi:10.1063/1.367292

Cited by 8 publications

(2 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The spectra were fitted with standard multi-oscillator lineshapes [21]. For sample 1, four oscillators were required, while three were sufficient for samples 2 and 3.…”

Section: Resultsmentioning

confidence: 99%

Effects of Confinement on the Coupling between Nitrogen and Band States in InGaAs1?xNx/GaAs (x ? 0.025) Structures: Pressure and Temperature Studies

Choulis

Weinstein

Hosea

et al. 2001

phys. stat. sol. (b)

View full text Add to dashboard Cite

“…The spectra were fitted with standard multi-oscillator lineshapes [21]. For sample 1, four oscillators were required, while three were sufficient for samples 2 and 3.…”

Section: Resultsmentioning

confidence: 99%

Effects of Confinement on the Coupling between Nitrogen and Band States in InGaAs1?xNx/GaAs (x ? 0.025) Structures: Pressure and Temperature Studies

Choulis

Weinstein

Hosea

et al. 2001

phys. stat. sol. (b)

View full text Add to dashboard Cite

“…They have been the subject of several experimental and theoretical investigations [1][2][3][4]. Although photoreflectance (PR) measurements have been widely conducted in these types of systems for the determination of the material parameters associated with the energies of spectral singularities, the physical origin of the PR lineshapes displayed behavior in the optical spectra that still deserves to be addressed more precisely [4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Lineshape analysis of photoreflectance spectra from InGaAs/GaAs quantum wells

Choque

Beliaev

Soares

et al. 1999

Superlattices and Microstructures

View full text Add to dashboard Cite

A new Fourier transform photo‐modulation spectroscopic technique for narrow band‐gap materials in the mid‐ to far‐infra‐red

Hosea

Merrick

Murdin

2005

Physica Status Solidi (a)

Self Cite

View full text Add to dashboard Cite

There is a large number of technologically important semiconducting optoelectronic materials with narrow band-gaps in the "finger-print" region of the infra-red (IR) spectrum. However, in many instances their band-structures have not been very well characterised, making it difficult to engineer their properties. Part of the reason is that the key non-destructive optical characterisation tool, modulation spectroscopy, becomes increasingly difficult as one attempts to look further out into the IR. To date, conventional diffraction-grating-based modulation spectroscopy has been applied predominantly below ~4 µm. We have developed a new photo-modulation system, based on a Fourier transform spectrometer, that permits such measurements out to much longer wavelengths. We discuss the advantages and technical difficulties of implementing such a system, and give the results obtained so far for narrower-gap materials, including bulk-like GaSb, InAs and InSb, comparing these with what can be obtained with conventional modulation spectroscopy arrangements. We apply our new technique to measure the bandgap in dilute-N InSbN, achieving what we believe are the first modulation spectroscopy measurements in the mid-IR beyond ~6 µm. optical property (e.g. transmittance, or more usually, reflectance R) is probed by a spectrally-resolved source while its dielectric function is being simultaneously externally modulated at frequency ν mod . In the case of reflectance, the modulated (AC) component, ∆R, is usually detected with sensitive lock-in techniques, yielding sharp, differential-like oscillatory spectra. In electro-modulated reflectance an applied AC electric field modulates any high resistance region in the structure directly. The most widely used version, photo-modulated reflectance (PR) [1] uses a chopped laser pump beam with photon energy above the band-gap. When the laser is on, generated carriers are captured by traps, thus reducing the inbuilt/surface electric fields. When the laser is off, the trap population, and hence field, are restored [2]. This mechanism modulates the Stark shift of, say, the quantum well (QW) levels which modulates the dielectric function, and thus the relative reflectivity, ∆R/R. Uninteresting broad background or systemresponse features in R are removed. At room temperature PR can give equivalent energy resolution to that obtained by PL and PLE at liquid helium temperatures, and probes a far wider range of critical point transition energies, yielding all these in a single spectrum, highlighting not only ground-state but also many higher-order critical point interband optical transitions, from which transition energies, and thus band-structure, can be accurately obtained. Unlike PLE, PR can be carried out using a white light blackbody radiator source (e.g. tungsten filament lamp), a simple diffraction grating spectrometer (e.g. 0.5 metre), and a small mechanically-chopped laser (such as a 3 mW, 633 nm HeNe) and so is applicable over a fairly wide wavelength range using the same equipment.Thus, modula...

show abstract

Modeling and analysis of photomodulated reflectance and double crystal x-ray diffraction measurements of tensilely strained InGaAs/InGaAsP quantum well structures

Cited by 8 publications

References 27 publications

Effects of Confinement on the Coupling between Nitrogen and Band States in InGaAs1?xNx/GaAs (x ? 0.025) Structures: Pressure and Temperature Studies

Effects of Confinement on the Coupling between Nitrogen and Band States in InGaAs1?xNx/GaAs (x ? 0.025) Structures: Pressure and Temperature Studies

Lineshape analysis of photoreflectance spectra from InGaAs/GaAs quantum wells

A new Fourier transform photo‐modulation spectroscopic technique for narrow band‐gap materials in the mid‐ to far‐infra‐red

Contact Info

Product

Resources

About