Deep-level characterization of <i>n</i>-type GaAs by photoreflectance spectroscopy

Kanata, T.; Matsunaga, M.; Takakura, Hideyuki; Hamakawa, Yoshihiro; Nishino, Taneo

doi:10.1063/1.348486

Cited by 24 publications

(4 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On one hand, the capture and emission rates of traps do not depend on the intensity of the beams and, on the other hand, traps are always energetically favorable to capture carriers. 8,11 Instead, the mechanism that is proposed by Shen et al in Ref. 8 is the modulation of the electric field by the surface photovoltage that is driven by the majority carrier dynamics.…”

Section: ͑E2͒mentioning

confidence: 95%

Optical electromodulation of surface-intrinsic-doped structures

Urı́as

Balderas

1997

Journal of Applied Physics

View full text Add to dashboard Cite

The modulation of the electric field within the intrinsic layer of surface-intrinsic-doped structures by means of a chopped pump beam and in the presence of a constant probe beam is calculated by considering the modulation of the surface voltage by the photoactivated majority carrier flow. The analysis is focused as to determine the dependency on the probe and pump photocurrents and on the chopping frequency of the observed rise and fall transient time constants of the time resolved photoreflectance signal. The non linear features of the carrier dynamics are worked out in detail. A rescaling of the time constants by the power of the probe beam is predicted.

show abstract

Section: ͑E2͒mentioning

confidence: 95%

Optical electromodulation of surface-intrinsic-doped structures

Urı́as

Balderas

1997

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…Conventional PR is done with a pump beam, usually a laser, that is modulated either by a mechanical chopper or by an acousto-optic modulator (AOM). Shen et al [2] among others [3][4][5][6][7] have shown PR to be a useful tool in studying the interface and surface charges that control the electric-field distribution in semiconductors. The basic PR mechanism is that the pump light, incident on the sample, creates electron-hole pairs that, as described below, modulate the surface field, which in turn modulates the reflectivity.…”

Section: Introductionmentioning

confidence: 98%

Effect of the modulation duty cycle on the amplitude of photoreflectance

Al-Arfaj

Glosser²,

Alavi³

et al. 2005

Can. J. Phys.

View full text Add to dashboard Cite

We have observed the behavior of photoreflectance (PR) spectra from a set of a molecular-beam-epitaxy-grown heterostructures as a function of the modulation duty cycle. This was done over a range of frequencies extending from 10-1000 Hz. By varying the duty cycle of the pump beam at different frequencies, we are able to find the duty cycle that gave the largest amplitude. While standard PR techniques use a 50% duty cycle, we have found that at low frequencies (10-30 Hz) the optimal value is between 30-40% in these particular sets of experiments resulting in as much as a 33% increase in amplitude. The change in the optimal values of the duty cycle from sample to sample was qualitatively correlated to the deep levels sample. PACS Nos.: 78.20.Ci, 78.40., 78.40.Fy Résumé : Nous avons étudié le spectre du facteur de réflexion (PR) sur un ensemble d'hétérostructures, développées par faisceau moléculaire épitaxial (MBE), en fonction de la modulation du cycle d'opération. Ceci a été complété sur un domaine de fréquences allant de 10 à 1000 Hz. En variant la fréquence du cycle d'opération du faisceau pompe, nous sommes capables de trouver le cycle d'opération qui donne la plus grande amplitude. Alors que les techniques PR usuelles utilisent un cycle d'opération de 50 %, nous trouvons qu'à basse fréquence [10 − 30 Hz] la valeur optimale est entre 30 % et 40 % pour ces ensembles particuliers d'expériences, résultant en une augmentation allant jusqu'à 33 % en amplitude. La variation du cycle d'opération optimal d'un échantillon à l'autre était qualitativement correlé à la profondeur des niveaux.[Traduit par la Rédaction]

show abstract

“…PR also proved to be useful for the determination of band gaps, potential barriers, and doping levels in layered semiconductor structures [2, 31. It was shown in [4] that the amplitude of PR signal is proportional to the magnitude of the photovoltage arising at a built-in potential barrier. Therefore, the times of photovoltage build-up and relaxation can be determined from the phase delay of the PR signal with respect to the pump illumination [5] and from the frequency dependence of the PR amplitude [6,7]. ') Pr.…”

Section: Introductionmentioning

confidence: 99%

Fourier resolution of surface and interface contributions to photoreflectance spectra of multilayered structures

Scheibler

Alperovich

Jaroshevich

et al. 1995

Phys. Stat. Sol. (a)

View full text Add to dashboard Cite

A technique for the determination of built‐in electric fields by Fourier transformation of Franz‐Keldysh oscillations in photoreflectance (PR) spectra is developed. This technique can be used for the resolution of “mixed” PR spectra originating from the surface and buried interfaces of layered semiconductor structures. Fourier transformation is especially effective in combination with phase‐resolved photo‐reflectance, which allows to change the relative amplitude of different PR spectral components. Model MBE‐grown GaAs structures with uniform surface electric fields are investigated. Along with the surface PR component, a component originated from the buffer‐substrate interface is extracted by Fourier transformation and phase resolution techniques. The energy band diagram of the structure is reconstructed. The Fermi level is shown to be pinned at the buffer‐substrate interface by defect‐induced electronic states.

show abstract

Deep-level characterization of n-type GaAs by photoreflectance spectroscopy

Cited by 24 publications

References 14 publications

Optical electromodulation of surface-intrinsic-doped structures

Optical electromodulation of surface-intrinsic-doped structures

Effect of the modulation duty cycle on the amplitude of photoreflectance

Fourier resolution of surface and interface contributions to photoreflectance spectra of multilayered structures

Contact Info

Product

Resources

About