Ambipolar diffusion measurements in semiconductors using nonlinear transient gratings

Jarašiūnas, K.; Gerritsen, H. J.

doi:10.1063/1.90270

Cited by 67 publications

(23 citation statements)

References 11 publications

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“…ql increases continuously with increasing temperature as it was found in the experiment at low IR-excitation of I,, = 4 MW em-2. The Il,(T)-curves calculated are in a good qualitative agreement with the experimental found behaviour of I,(T) taking into consideration the approximative character of (8) and ( decreases with increasing temperature in qualitative agreement with the experimentally observed behaviour (Fig. 5) , where a linear connection was found between I,, and the generated exciton density N,,, in the case of one-photon interband excitation.…”

Section: Temperature Dependencesupporting

confidence: 86%

Transient Light‐Induced Gratings Due to Excitons in CdSe

Rückmann

Jarašiūnas²,

Gaubas³

1985

Physica Status Solidi (b)

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Transient light-induced grat,ings due to free carriers and excitons are created in CdSe in a medium density range of lOI5 to 1017 by two coherent intense (ns) IR-pump beams. Detailed investigations of probe-beam diffraction due to thin excitonic gratings in the spectral region just below the A,=l-exciton line a t 85 K and its dependence on sample temperature and on the excitation level are presented. First-order diffraction efficiences up to 5% and a nonlinear dependence of diffraction on the excitation level can be observed. For the first time numerical calculations of probe-beam diffraction due to excitonic phase and amplitude gratings are presented. The comparison with the experiment shows, that the damping of a dense exciton gas increases proportional to the excitation intensity in the case of two-photon interband excitation, and that the lightinduced absorptive changes Aha due to dense excitone dominate over the dispersive changes An in the spectral region under consideration. Mittels zweier, kohirenter und intensiver (ns) IR-Pumpstrahlen werden lichtinduzierte Gitter in CdSe, hervorgerufen durch freie Triiger und Exzitonen in einem mittleren Dichtebereich vonlox5 bis IOl7 cm-s, erzeugt. Vorgestellt werden detaillierte Untersuchungen der Probenstrahlbeugung an dunnen exzitonischen Gittern bei 85 K sowie deren Temperatur-und Intensitatsabhiingigkeiten im Spektralbereich nahe unterhalb der A, = 1-Exzitonenlinie. Beugungseffizienzen in der 1. Ordnung bis zu 5% und eine nichtlineare Intensitatsabhiingigkeit der Beugung werden beobachtet. Erstmalig werden numerische Berechnungen der Lichtbeugung an exzitonischen Phasen-und Amplitudengittern vorgestellt. Der Vergleich mit dem Experiment zeigt ein proportionales Wachsen der exzitonischen Dampfung mit der Anregungsintensitat im Falle der ZweiPhotonen-Interbandanregung sowie das Dominieren der durch das erzeugte dichte Exzitonengas hervorgerufenen licht-induzierten absorptiven hderungen Acu iiber die dispersiven hderungen An im betrachteten Spektralbereich.

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Section: Temperature Dependencesupporting

confidence: 86%

Transient Light‐Induced Gratings Due to Excitons in CdSe

Rückmann

Jarašiūnas²,

Gaubas³

1985

Physica Status Solidi (b)

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“…Laser-induced transient grating (TG) technique [19] is one of powerful methods to study photo-induced reactions, such as the diffusion processes of short-lived radicals [20], intermediates of protein reactions [21,22], or carrier diffusion in semiconductors [23,24]. Recently, we investigated the formation of Pt particles during the photoirradiation in the PVP solutions by means of the TG method [25].…”

Section: Introductionmentioning

confidence: 99%

Diffusion of gold ions and gold particles during photoreduction processes probed by the transient grating method

Harada

Okamoto

Terazima

2009

Journal of Colloid and Interface Science

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“…the dependence of diffraction efficiency on optical excitation energy. Aside from the well established fact that EC is very informative if carrier generation mechanisms have to be characterized [5], we demonstrate as well that this type of dependence, under certain experimental conditions, contains valuable information on carrier recombination and transport.…”

Section: Introductionmentioning

confidence: 95%

Space-charge limited free carrier transport in semi-insulating III-V compounds

Sūdžius

Kadys

Jarašiūnas

2004

13th International Conference on Semiconducting and Insulating Materials, 2004. SIMC-XIII-2004.

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We demonstrate a novel way to analyse carrier recombination and transport processes in photorefractive semiconductors via kinetics and exposure characteristics of light induced diffraction. The results of a picosecond degenerate four-wave mixing on free carrier gratings in semi-insulating GaAs and InP bulk crystals are discussed. The role of a deep trap recharging in carrier diffusion and recombination is sensitively revealed through a feedback effect of a space-charge field to nonequilibrium carrier transport or directly through linear electrooptic effect. IntroductionDegenerate four-wave mixing (DFWM) has been demonstrated to be a sensitive tool for studying carrier generation, transport, and recombination processes in bulk crystals, epilayers, and heterostructures [1,2]. In particular, the technique provides good means for nondestructive characterization of deep-impurity-related effects in semi-insulating (SI) materials by monitoring the formation of light-induced space-charge (SC) field E sc either through a linear electrooptic effect [3] or indirectly through its feedback to nonequilibrium carrier transport [4]. For this goal, the kinetics of free carrier grating at small grating periods Λ (because of relationship E sc ~ 1/Λ ) and various excitations are usually measured.In the given work, we present a novel way to study deep-impurity-related photoelectrical processes in SI GaAs and InP bulk crystals by exploring the features of exposure characteristics (EC) of diffraction, i.e. the dependence of diffraction efficiency on optical excitation energy. Aside from the well established fact that EC is very informative if carrier generation mechanisms have to be characterized [5], we demonstrate as well that this type of dependence, under certain experimental conditions, contains valuable information on carrier recombination and transport. Experimental Results and DiscussionA mode-locked Nd:YAG laser at λ = 1064 nm wavelength (hν = 1.17 eV) has been used for recording and probing of transient gratings [6]. The pulse width was 27 ps at FWHM. The incident laser beam was divided into two s-polarized parts of approximately equal energy which recombined at an angle Θ to form a grating with period Λ = λ / [2 sin(Θ / 2)] in the bulk of the crystal. The decay of a transient grating as well as its dependence on the excitation energy I 0 was studied by Bragg diffraction of the probe beam I prb [6]. The setup enabled us to record the diffracted signal I 1 on free carrier (FC) grating (p-diffracted component of p-polarized probe beam) or photorefractive (PR) grating (p-diffracted component of s-polarized probe beam). In both cases, the diffraction efficiency η has been defined as a ratio of the diffracted signal intensity to the transmitted signal intensity. Further details on

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Ambipolar diffusion measurements in semiconductors using nonlinear transient gratings

Cited by 67 publications

References 11 publications

Transient Light‐Induced Gratings Due to Excitons in CdSe

Transient Light‐Induced Gratings Due to Excitons in CdSe

Diffusion of gold ions and gold particles during photoreduction processes probed by the transient grating method

Space-charge limited free carrier transport in semi-insulating III-V compounds

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