DLTS study of InGaAs and GaAsN structures with different indium and nitrogen compositions

Kósa, A.; Stuchlíková, Ł.; Harmatha, L.; Kováč, J.; Ściana, B.; Dawidowski, Wojciech; Tłaczała, M.

doi:10.1016/j.mssp.2017.10.035

Cited by 8 publications

(6 citation statements)

References 23 publications

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“…Generally speaking, a higher leakage current, if not related to a parallel resistance component, can be associated with an increased concentration of defects in proximity of the junction, possibly indicating an increased defectiveness of group C devices compared to shorter wavelength LEDs. Assuming that tuning of the emission wavelength was achieved through compositional variations rather than through QW width adjustments [ 16 ], this may be ascribed to the higher indium content in the semiconductor alloy, that may favor higher defectiveness and the conduction mechanisms, such as trap-assisted tunneling, that typically dominate in the low forward bias regime [ 17 , 18 ]. The higher defectiveness of group C devices was also confirmed by the analysis of the bias-dependent ideality factor, reported here for a representative sample of each group in Figure 1 c. The experimental data show that even in an unaged state, LEDs belonging to group C exhibit a higher ideality factor, with values close to 2 at 0.45 V. An ideality factor close to 2 typically indicates a conduction regime dominated by defect-related recombination currents within the space-charge region of the device; therefore, this finding further suggests that group C devices are affected by a higher concentration of defects in the proximity of, or within, their active region.…”

Section: Methodsmentioning

confidence: 99%

Gradual Degradation of InGaAs LEDs: Impact on Non-Radiative Lifetime and Extraction of Defect Characteristics

et al. 2021

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We present a detailed analysis of the gradual degradation mechanisms of InGaAs Light-Emitting Diodes (LEDs) tuned for optical emission in the 1.45–1.65 μm range. Specifically, we propose a simple and effective methodology for estimating the relative changes in non-radiative lifetime, and a procedure for extracting the properties of defects responsible for Shockley-Read-Hall recombination. By means of a series of accelerated aging experiments, during which we evaluated the variations of the optical and electrical characteristics of three different families of LEDs, we were able to identify the root causes of device degradation. Specifically, the experimental results show that, both for longer stress time at moderate currents or for short-term stress under high injection levels, all the devices are affected: (i) by a partial recovery of the optical emission at the nominal bias current; and (ii) by a decrease in the emission in low-bias regime. This second process was deeply investigated, and was found to be related to the decrease in the non-radiative Shockley-Read-Hall (SRH) lifetime due to the generation/propagation of defects within the active region of the LEDs. Devices tuned for longer-wavelength emission exhibited a second degradation process, which was found to modify the carrier injection dynamics and further speed-up optical degradation in the low bias regime. These processes were ascribed to the effects of a second non-radiative recombination center, whose formation within the active region of the device was induced by the aging procedure. Through mathematical analysis of the degradation data, we could quantify the percentage variation in SRH lifetime, and identify the activation energy of the related defects.

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Section: Methodsmentioning

confidence: 99%

Gradual Degradation of InGaAs LEDs: Impact on Non-Radiative Lifetime and Extraction of Defect Characteristics

et al. 2021

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“…GaAsN layers grown in our system exhibit a low electron concentration in the range of 10 16 cm −3 . Detailed growth parameters can be found elsewhere [5,7,16,45]. After growth, the epitaxial structure was divided into smaller parts.…”

Section: Structure Growth and Device Preparationmentioning

confidence: 99%

“…The relatively low EQE signal of the GaAsN solar cell is probably related to typical dilute nitride material imperfections. The most common disadvantages of GaAsN are its short minority carrier lifetime [26,27], high background doping concentration [8,9] and, finally, the nitrogeninduced defects [4,5,45]. Moreover, the fabrication of anti-reflective coating (not applied on the examined structure) on the solar cell surface should increase the EQE signal [47].…”

Section: Electrical and Electro-optical Characterizationmentioning

confidence: 99%

“…The detailed measurement conditions can be found elsewhere [5,45,96]. A typical DLTFS spectrum of the GaAsN solar cell structure is presented in Figure 10a, where the positive value of measured capacitance signal indicates that the detected deep levels in GaAsN structure are majority carrier (electron) traps.…”

Section: Deep Level Transient Fourier Spectroscopy Investigationsmentioning

confidence: 99%

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Analysis of Current Transport Mechanism in AP-MOVPE Grown GaAsN p-i-n Solar Cell

et al. 2021

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Basic knowledge about the factors and mechanisms affecting the performance of solar cells and their identification is essential when thinking of future improvements to the device. Within this paper, we investigated the current transport mechanism in GaAsN p-i-n solar cells grown with atmospheric pressure metal organic vapour phase epitaxy (AP-MOVPE). We examined the electro-optical and structural properties of a GaAsN solar cell epitaxial structure and correlated the results with temperature-dependent current-voltage measurements and deep level transient spectroscopy findings. The analysis of J-V-T measurements carried out in a wide temperature range allows for the determination of the dominant current transport mechanism in a GaAsN-based solar cell device and assign it a nitrogen interstitial defect, the presence of which was confirmed by DLTFS investigation.

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“…El estudio de semiconductores III-V como: GaAs, InGaAs, GaAsN, InGaP ha sido objeto de interés en los últimos años debido a la versatilidad de sus propiedades ópticas y eléctricas, para aplicaciones en el desarrollo de dispositivos optoelectrónicos y en la tecnología fotovoltaica [1,2,3,4,5,6]. Con el fin de incrementar el espectro de aplicaciones y generar reducción de los costos de producción, la investigación reciente se centra en la obtención de este tipo de aleaciones semiconductoras utilizando nuevas estrategias originando una importante actividad en el desarrollo y estudio de nuevos materiales [7,8].…”

Section: Introducciònunclassified

Segregación de Mn en películas delgadas de GaAsMn obtenidas mediante pulverización catódica

et al. 2020

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RESUMEN Actualmente, la fabricación de películas delgadas de GaAs dopadas con Mn (GaAsMn) sobre Si (100), es un objeto de gran interés debido a su posible integración con la tecnología del silicio, generando un desarrollo significativo en la funcionalidad de los dispositivos optoelectrónicos y espintrónicos. En este trabajo, presentamos un estudio sistemático de la caracterización estructural, morfológica, óptica, y magnética de películas delgadas de GaAsMn preparadas por pulverización catódica R.F sobre un substrato de silicio (100), para temperaturas del crecimiento de 100 y 200 oC, respectivamente. A partir de los espectros Raman se identificaron los modos vibracionales, trasversal óptico (TO) y longitudinal óptico (LO) de GaAs, localizados en 290 cm-1 y 265 cm-1, respectivamente. Adicionalmente, se identificaron modos vibracionales de MnAs, debido a la substitucion de átomos de Ga por átomos de Mn en altas concentraciones. La segregación de Mn, fue corroborada mediante difracción de rayos-X, en donde se evidencian planos cristalinos en las direcciones (400) y (200) de GaAs policristalino, y planos cristalográficos pertenecientes a fases de Mn1+xAs. La morfología y el modo de crecimiento de las películas delgadas de GaAsMn/Si (100), se llevó a cabo mediante imágenes de microscopía de fuerza atómica (AFM) y microscopía electrónica de barrido (SEM) tomadas sobre la superficie y en sección transversal, respectivamente. Finalmente, un análisis de las propiedades magnéticas de las películas delgadas de GaAsMn a partir de imágenes de microscopía de fuerza magnética (MFM), revelan la presencia de dominios magnéticos superficiales provenientes de MnAs. Concluimos que las propiedades físicas de las películas de GaAsMn dependen de las condiciones de crecimiento.

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DLTS study of InGaAs and GaAsN structures with different indium and nitrogen compositions

Cited by 8 publications

References 23 publications

Gradual Degradation of InGaAs LEDs: Impact on Non-Radiative Lifetime and Extraction of Defect Characteristics

Gradual Degradation of InGaAs LEDs: Impact on Non-Radiative Lifetime and Extraction of Defect Characteristics

Analysis of Current Transport Mechanism in AP-MOVPE Grown GaAsN p-i-n Solar Cell

Segregación de Mn en películas delgadas de GaAsMn obtenidas mediante pulverización catódica

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