Comparative Studies of Carrier Dynamics in 3C-SiC Layers Grown on Si and 4H-SiC Substrates

Ščajev, Patrik; Hassan, Jawad; Jarašiūnas, K.; Kato, Masashi; Henry, Anne; Bergman, J. P.

doi:10.1007/s11664-010-1378-y

Cited by 19 publications

(14 citation statements)

References 24 publications

(26 reference statements)

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“…The LPV as a function of laser position data in figure 3(c) can be fitted into equation ( 8) [48]. For instance, with 500 µm-spacing device under 637 nm and 980 nm (100 µW) illumination, the data can be fitted with L = 250 µm and L h = 2.3 µm [49]. The fitting result is shown in figure S4, with the fitted values of K for 637 nm and 980 nm are 0.981 and 0.982, respectively.…”

Section: Resultsmentioning

confidence: 99%

Effects of photogenerated-hole diffusion on 3C-SiC/Si heterostructure optoelectronic position-sensitive detector

Nguyen¹,

Foisal²,

Nguyen³

et al. 2021

J. Phys. D: Appl. Phys.

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Single-crystalline silicon carbide (3C-SiC) has been attracting significant attention in recent years due to its cost-effectiveness and high crystalline quality, mature fabrication techniques on Si-substrate and outstanding mechanical, chemical, and optoelectronic characteristics. Taking advantage of its large built-in potential, a promising application of 3C-SiC on Si (3C-SiC/Si) heterostructure is to develop position-sensitive detectors (PSDs) based on the lateral photovoltaic effect. The lateral photovoltage is generated under non-uniform illumination due to the asymmetry diffusion of photo-induced charge carriers. However, the full potential of 3C-SiC/Si heterojunction-based PSDs has not been elucidated yet. In this study, we investigate the influence of photogenerated hole and its diffusion path length on the sensing performance of the devices in attempts to obtain an optimal design and further pushing the limit of the PSD. Devices with different electrode spacings are fabricated on the 3C-SiC/Si heterostructure, and experiments are conducted under different illumination conditions to determine the position-sensitivity. Devices with short electrode spacings are found to have excellent position-sensitivity with the highest sensitivity of 470 mV mm−1 obtained in a device spacing of 300 µm under 980 nm (1000 µW) laser illumination. The physic mechanism underneath the experimentally observed behaviors are explained based on the generation and separation of electron–hole (e–h) pairs under the illumination, and charge carrier diffusion theory. The findings of this work will provide insights to design highly sensitive PSDs and explore its full potentials.

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Section: Resultsmentioning

confidence: 99%

Effects of photogenerated-hole diffusion on 3C-SiC/Si heterostructure optoelectronic position-sensitive detector

Nguyen¹,

Foisal²,

Nguyen³

et al. 2021

J. Phys. D: Appl. Phys.

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“…The τ G values were estimated on basis of the measured carrier lifetimes τ R in 0.5 ns -1 µs range [2,16] and diffusive decay times τ D > 230 ps for used period Λ = 2.85 µm (the D values for 3C SiC varied in 1.5 -9 cm 2 /s interval with temperature [4], and similarly in the other polytypes). Therefore diffraction efficiency value if measured at the end of laser pulse (t ≈ 20 ps) was not affected by the grating decay and reflected the instantaneus values of ∆n.…”

Section: Samplesmentioning

confidence: 99%

“…A deeper understanding of these processes in high-density carrier plasma can be obtained by applying time-resolved optical techniques, which allow the injection of an excess carriers by a short laser pulse and subsequent monitoring of the recombination and diffusion processes [1][2][3][4][5][6][7]. Therefore knowledge of absorption coefficent at commonly used laser wavelengths is an important issue for more precise determination of injected carrier density profile and related plasma parameters in SiC, e.g.…”

Section: Introductionmentioning

confidence: 99%

A diffraction-based technique for determination of interband absorption coefficients in bulk 3C-, 4H- and 6H-SiC crystals

Ščajev¹,

Kato²,

Jarašiūnas³

2011

J. Phys. D: Appl. Phys.

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Knowledge of an absorption coefficent values for wavelenghts above the bandgap and the injected carrier density profile is an important issue for analysis of carrier dynamics in highly excited semiconductors, e.g. for evaluation of the carrier density in photoexcited layer, density-dependent recombination rate, and diffusivity. In this work we present a novel way for determining the interband absorption coefficient α for SiC crystals in a wide temperature range. The proposed method is based on recording of a transient free carrier grating in a bulk semiconductor by strongly absorbed light and measurements of a probe beam diffraction efficiencies on the grating for Bragg and symmetric anti-Bragg directions. The method was applied for 3C-, 6H-, 4H-SiC polytypes at 351 nm wavelength and revealed 3 to 10-fold increase of the interband absorption coefficients in 80-800 K temperature range. Increase of absorption coefficients with temperature was simulated by bandgap shrinkage and increase of phonon density. A good agreement of the determined α values with a priori known room-temprature data verified validation of this technique.

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“…Lifetime decrease with nitrogen doping, not correlating with the Z 1/2 trap density, was also observed in [7]. The recombination mechanisms when intrinsic Z 1/2 trap density is negligibly low are often attributed to surface recombination, dislocations and stacking faults [8][9][10][11]. Few works also indicate that other point defects cannot be neglected [2,12].…”

Section: Introductionmentioning

confidence: 96%

Recombination and diffusion processes in electronic grade 4H silicon carbide

Ščajev¹,

Subačius²,

Jarašiūnas³

et al. 2019

physics

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Carrier dynamics in n-type 4H-SiC epilayers of varying thicknesses and low Z1/2 defect concentrations are investigated here in wide ranges of excess carrier density and temperature. Several techniques are employed to monitor carrier diffusion and recombination processes, including light induced transient grating (LITG), microwave photoconductance decay (MPCD) and free carrier absorption (FCA) using ps-laser pulses at 355 nm. The observed increase of the diffusion coefficient with the increasing excitation level is explained by the transition from the minority to the bipolar transport regime. Its subsequent decrease with even higher excitations is found to be governed by band-gap renormalization and degeneracy effects. The bulk lifetime, limited by hole traps at 0.19–0.24 eV above the valence band at lower excitations, was found to decrease from few microseconds to hundreds of nanoseconds during the transition regime from the minority to the bipolar transport. Our temperature-dependent measurements confirmed the trap activation energy and provided the approximate functional form of electron and hole lifetimes as τe = 340 × (T/300 K)3/2 ns and τh = 100 × (T/300 K)–1/2 ns, for the temperature T range 80–800 K. It was found to hold for 65 and 120 μm sample thicknesses, while the lifetimes were found to be twice shorter for the sample 35 μm thick.

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Comparative Studies of Carrier Dynamics in 3C-SiC Layers Grown on Si and 4H-SiC Substrates

Cited by 19 publications

References 24 publications

Effects of photogenerated-hole diffusion on 3C-SiC/Si heterostructure optoelectronic position-sensitive detector

Effects of photogenerated-hole diffusion on 3C-SiC/Si heterostructure optoelectronic position-sensitive detector

A diffraction-based technique for determination of interband absorption coefficients in bulk 3C-, 4H- and 6H-SiC crystals

Recombination and diffusion processes in electronic grade 4H silicon carbide

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