Control of intermediate-band configuration in GaAs:N δ-doped superlattice

Osada, Kazuki; Suzuki, Tomoya; Yagi, Shuhei; Naitoh, Shunya; Yoshida, Shoji; Hijikata, Yasuto; Okada, Yoshitaka; Yaguchi, Hiroyuki

doi:10.7567/jjap.54.08ka04

Cited by 9 publications

(6 citation statements)

References 32 publications

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“…The commonly observed PR signals at 1.15 eV originated from the E − band of the IB absorber. The energy level related to the E + band of GaAs:N with the δ-doped superlattice structure lies at a lower energy (~1.5 eV above the VB edge) than those of conventional GaAsN alloys, [26][27][28][29] although those were not clearly observed in the obtained spectra probably because signals from other layers covered them. Based on the PR measurements, barrier height seen from the IB level can be estimated to be 0.27, 0.42, and 0.58 eV for the EBL Al composition =…”

Section: Resultsmentioning

confidence: 76%

Effects of carrier-blocking barrier height on two-step photocurrent generation in dilute nitride intermediate band solar cells

Yagi

Numata

Yoshida

et al. 2023

Jpn. J. Appl. Phys.

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GaAs:N dilute nitride intermediate band solar cells (IBSCs) with different barrier height for blocking electron transport from the intermediate band (IB) were prepared and the role of such an electron blocking layer (EBL) was investigated. It is found that the EBL effectively confines electrons in the IB states, and two-step photocurrent generation process is strongly affected by its barrier height. A rate equation analysis well reproduced experimental observations of the applied voltage dependence of the two-step photocurrent generation process. It revealed that the electron extraction both from the conduction band and the IB through the EBL is governed by thermionic emission process. To meet the requirements of an ideal IBSC, optimized device structures including the barrier height of the EBL have to be designed properly taking into account the material parameters and carrier dynamics under the actual operating condition.

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Section: Resultsmentioning

confidence: 76%

Effects of carrier-blocking barrier height on two-step photocurrent generation in dilute nitride intermediate band solar cells

Yagi

Numata

Yoshida

et al. 2023

Jpn. J. Appl. Phys.

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“…Detailed discussions of the structural dependence of the energy configuration in the SLs are given in our other publications. 29,30)…”

Section: Structural and Optical Characterizations Of Gaas:n δ-Doped Slsmentioning

confidence: 99%

Molecular beam epitaxial growth of intermediate-band materials based on GaAs:N δ-doped superlattices

Suzuki

Osada

Yagi

et al. 2015

Jpn. J. Appl. Phys.

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We fabricated GaAs:N δ-doped superlattices (SLs) by molecular beam epitaxy and investigated their potential as an intermediate-band photoabsorber in high-efficiency solar cells. The N area concentration in a N δ-doped layer was well controlled by adjusting the fabrication conditions, and the SLs with the average N composition of up to 1.5% were obtained. The SL minibands related to the N-induced E + and E % conduction subbands were formed with well-separated bottom energies of up to 0.4 eV, indicating the suitability of this material system for use in intermediate-band solar cells. A two-step photoabsorption process in a solar cell with the SL absorber was successfully demonstrated through external quantum efficiency measurements under additional infrared illumination at room temperature.

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“…The alloys of GaAs-GaN provide the opportunity to fabricate GaAsN which recently attract the attention because of their negative and large band bowing (from -7 to -40 eV) largely dependent on compositional properties. The offset of conduction band (>300 meV) is due to the size and electro-negativity difference among N, Ga and As atoms [4,5]. The new sub-bands of energy can be constructed in the region of the lower energy of the conduction band by the addition of N inside the GaAs host materials which can be described by the band anti-crossing model and constitute intermediate band solar cell structure (IBSC).…”

Section: Introductionmentioning

confidence: 99%

Design and analysis of GaAsN based solar cell for harvesting visible to near-infrared light

Haque¹,

Ali²,

Hossain³

et al. 2022

Phys. Scr.

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In the present study, the performance parameters of GaAsN dilute nitride-based semiconductor solar cell with and without AlGaAs blocking layers have been investigated in detail by Solar Cell Capacitance Simulator in one dimensional software program (SCAPS-1D). The thickness of absorber, buffer, and blocking layers are varied to achieve the improvement of open circuit voltage, short circuit current, fill factor, efficiency and also to optimize the device structure. The impact of doping and defect densities on the solar cell performance parameters have been analyzed minutely inside the absorber, buffer, and blocking layers. The solar cell thermal stability parameters are also investigated in the temperature region from 273K to 373K. The efficiency of 43.90% and 40.05% are obtained from the proposed solar cells with and without AlGaAs blocking layer, respectively. The present findings may provide insightful approach for fabricating feasible, cost effective, and efficient dilute nitride solar cell.

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Control of intermediate-band configuration in GaAs:N δ-doped superlattice

Cited by 9 publications

References 32 publications

Effects of carrier-blocking barrier height on two-step photocurrent generation in dilute nitride intermediate band solar cells

Effects of carrier-blocking barrier height on two-step photocurrent generation in dilute nitride intermediate band solar cells

Molecular beam epitaxial growth of intermediate-band materials based on GaAs:N δ-doped superlattices

Design and analysis of GaAsN based solar cell for harvesting visible to near-infrared light

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