Enhancement of the Excitonic Photoluminescence in n+/i-GaAs by Controlling the Thickness and Impurity Concentration of the n+Layer

Čerškus, Aurimas; Nargelienė, Viktorija; Kundrotas, J.; Sužiedėlis, Algirdas; Ašmontas, Steponas; Gradauskas, Jonas; Johannessen, Agne; Johannessen, Erik

doi:10.12693/aphyspola.119.154

Cited by 6 publications

(4 citation statements)

References 23 publications

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“…Similar effects were observed in Si-doped n + /n-GaAs homojunction structures [19], Si δ-doped GaAs structures [20], in selectively Sidoped GaAs/AlGaAs heterostructures [21] as well as in AlInN/GaN heterostructures [22]. Theoretical calculations show that a strong electric field is induced in all of these structures at the interface side of the active layer.…”

Section: Discussionsupporting

confidence: 65%

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Photoluminescence lifetimes in GaAs/Al0.3Ga0.7As structures designed for microwave and terahertz detectors

Čerškus¹,

Kundrotas²,

Nargelienė³

et al. 2013

Lith. J. Phys.

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This paper presents the photoluminescence spectra and light emission lifetimes in GaAs/Al 0.3 Ga 0.7 As structures designed for microwave and terahertz detectors. The photoluminescence and light emission lifetimes were investigated both before and after etching of the cap-layers, and possible mechanisms of carrier recombination are discussed. The characteristic time of the free exciton emission corresponds to 0.5 ns at a temperature of 3.6 K. The recombination lifetime of the free electron acceptor was measured to be 22-25 ns in GaAs structures and 4-15 ns in AlGaAs structures. The emission lifetime of deep Si level having 170 meV activation energy in AlGaAs layer was found to be equal to 40 ns. The excitonic photoluminescence maxima of n + /n-GaAs and n + /n-Al 0.3 Ga 0.7 As homojunction structures in comparison to n-GaAs and n-Al 0.3 Ga 0.7 As were shifted by approximately 200 ps. This suggested that the drift of free carriers is important in the formation of free excitons in n-GaAs and n-Al 0.3 Ga 0.7 As layers.

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Section: Discussionsupporting

confidence: 65%

“…However, this model cannot fully explain the excitonic emission enhancement observed at low temperatures. More widely this problem has also previously been discussed in literature [19].…”

Section: Discussionmentioning

confidence: 85%

Photoluminescence lifetimes in GaAs/Al0.3Ga0.7As structures designed for microwave and terahertz detectors

Čerškus¹,

Kundrotas²,

Nargelienė³

et al. 2013

Lith. J. Phys.

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“…A more detailed discussion about the influence of surface on the enhancement of continuous PL intensity is presented in Ref. (12).…”

Section: Resultsmentioning

confidence: 99%

The Increase of Radiative Lifetime of Free Excitons in Selectively Si-doped GaAs/AlxGa1-xAs Heterostructures

Kundrotas

Čerškus

Nargelienė

et al. 2014

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The time resolved photoluminescence spectra of selectively Si-doped GaAs/Al x Ga 1-x As heterostructures have been investigated over a wide temperature range from 3.6 K to 300 K in order to identify possible mechanisms behind the observed increase in radiative lifetime of free excitons. Possible mechanisms of carrier recombination are discussed with emphasis on the unique traits of excitonic photoluminescence. The intensive lines found in the spectra of the heterostructures are associated with the formation and enhancement of free exciton emission in the flat band region of an active i-GaAs layer. We have established that the free exciton radiative lifetime in the heterostructures increases about two times, up to 1.44 ns in comparison with lifetime 0.6 ns of i-GaAs layer without a heterostructure for first sample and up to 0.92 ns from 0.4 ns for second sample at 3.6 K temperature.

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“…This enhancement is related to a built-in electric field in n + /n-homojunctions [18]. The recombination process is more complex in n + /n-GaAs or n + /n-Al x Ga 1−x As homostructures or in selectively doped heterostructures or δ-doped structures [29][30][31] compared to undoped or lightly doped double heterostructures [32][33][34]. The incident laser beam generates electron-hole pairs at a certain depth, and the photogenerated carriers can form excitons in the GaAs or Al x Ga 1−x As layer.…”

Section: Resultsmentioning

confidence: 99%

Dynamic photoluminescence studies of vertical n⁺/n-GaAs/Al_0.2Ga_0.8As structures designed for microwave electronics

Čerškus¹,

Kundrotas²,

Nargelienė³

et al. 2013

Phys. Scr.

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Vertical structures of n + /n-GaAs/Al 0.2 Ga 0.8 As designed as radiation detectors for microwave electronics have been the subject of continuous wave and dynamic photoluminescence studies. Both light emission lifetimes and photoluminescence spectra were investigated to find the possible mechanisms of carrier recombination. The characteristic time of free exciton emission in the n-GaAs layer corresponds to 0.73 ns at a temperature of 3.6 K, 1.1 ns at 77 K and 1.3 ns at 300 K. The band-to-band transition lifetimes in the n-GaAs layer are found to be 2.8 ns at 77 K and 3.8 ns at 300 K. The recombination lifetime of a free electron via an acceptor was measured to be 22 ns in the GaAs layer and 16 and 32 ns in the n-Al 0.2 Ga 0.8 As layer, reflecting the two different transitions observed. The short characteristic time of the excitonic transitions in the n-Al 0.2 Ga 0.8 As layer permits the excitonic emission to follow laser excitation pulses down to the order of 200 ps.

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Enhancement of the Excitonic Photoluminescence in n⁺/i-GaAs by Controlling the Thickness and Impurity Concentration of the n⁺Layer

Cited by 6 publications

References 23 publications

Photoluminescence lifetimes in GaAs/Al<sub>0.3</sub>Ga<sub>0.7</sub>As structures designed for microwave and terahertz detectors

Photoluminescence lifetimes in GaAs/Al<sub>0.3</sub>Ga<sub>0.7</sub>As structures designed for microwave and terahertz detectors

The Increase of Radiative Lifetime of Free Excitons in Selectively Si-doped GaAs/AlxGa1-xAs Heterostructures

Dynamic photoluminescence studies of vertical n⁺/n-GaAs/Al_0.2Ga_0.8As structures designed for microwave electronics

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Enhancement of the Excitonic Photoluminescence in n+/i-GaAs by Controlling the Thickness and Impurity Concentration of the n+Layer

Cited by 6 publications

References 23 publications

Photoluminescence lifetimes in GaAs/Al<sub>0.3</sub>Ga<sub>0.7</sub>As structures designed for microwave and terahertz detectors

Photoluminescence lifetimes in GaAs/Al<sub>0.3</sub>Ga<sub>0.7</sub>As structures designed for microwave and terahertz detectors

The Increase of Radiative Lifetime of Free Excitons in Selectively Si-doped GaAs/AlxGa1-xAs Heterostructures

Dynamic photoluminescence studies of vertical n+/n-GaAs/Al0.2Ga0.8As structures designed for microwave electronics

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Enhancement of the Excitonic Photoluminescence in n⁺/i-GaAs by Controlling the Thickness and Impurity Concentration of the n⁺Layer

Dynamic photoluminescence studies of vertical n⁺/n-GaAs/Al_0.2Ga_0.8As structures designed for microwave electronics