Enhanced nitrogen incorporation by pulsed laser annealing of GaNxAs1−x formed by N ion implantation

Yu, K. M.; Walukiewicz, W.; Beeman, J. W.; Scarpulla, Michael A.; Pillai, Manoj R.; Aziz, Michael J.

doi:10.1063/1.1481196

Cited by 29 publications

(25 citation statements)

References 20 publications

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“…Compared to films produced by N + implantation and rapid thermal annealing only, the introduction of PLM improves N incorporation by a factor of five. It was found that subsequent RTA at temperatures higher than ~700ºC after PLM was essential in obtaining good quality GaN x As 1-x thin films with clear optical transitions [26]. The optical properties and crystalline quality of these films are comparable to GaN x As 1-x thin films of similar composition made by epitaxial growth techniques.…”

Section: Nitrogen Activation Efficiencymentioning

confidence: 64%

“…In a previous report, we demonstrated that pulsed laser melting followed by rapid thermal annealing (PLM-RTA) greatly enhanced the incorporation of substitutional N in N + -implanted GaAs [26]. Films implanted with 1.8% N exhibited a fundamental band gap of 1.26eV (a band gap reduction of 160meV), corresponding to an N activation efficiency of ~50%.…”

Section: Nitrogen Activation Efficiencymentioning

confidence: 99%

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Synthesis of GaNxAs1−x thin films by pulsed laser melting and rapid thermal annealing of N+-implanted GaAs

Walukiewicz

Scarpulla

et al. 2003

Journal of Applied Physics

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We present a systematic investigation on the formation of the highly mismatched alloy GaN x As 1-x using N + -implantation followed by a combination of pulsed laser melting and rapid thermal annealing. Thin films of GaN x As 1-x with x as high as 0.016 and an activation efficiency of the implanted N up to 50% have been synthesized with structural and optical properties comparable to films grown by epitaxial deposition techniques with similar substitutional N content. The effects of N + implantation dose, laser energy fluence and rapid thermal annealing temperature on the N incorporation as well as optical and structural properties of the GaN x As 1-x films are discussed.

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Section: Nitrogen Activation Efficiencymentioning

confidence: 64%

Section: Nitrogen Activation Efficiencymentioning

confidence: 99%

Synthesis of GaNxAs1−x thin films by pulsed laser melting and rapid thermal annealing of N+-implanted GaAs

Walukiewicz

Scarpulla

et al. 2003

Journal of Applied Physics

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“…The highest reported As content in MOVPE grown layers is x~0.067 [10,11,12]. Even lower maximum As contents of x~0.0026 [19] and x~0.01 [20] were achieved in MBE layers grown at .750 o C and at 500 o C, respectively Recently, materials with constituents having drastically different chemical or physical properties at compositions or structures far exceeding their thermodynamic solubility and stability limits have been synthesized using extreme non-equilibrium synthesis techniques [21,22,23]. The atomic diffusion length in these non-equilibrium processes is long enough to form crystalline lattices with uniform compositions, but short enough to avoid equilibrium phase segregation.…”

Section: Low Temperature Molecular Beam Epitaxial Growth Of Ga-n-asmentioning

confidence: 99%

“…For both techniques, it is difficult to obtain a high concentration of As in the alloy before phase separation occurs. The 6 highest reported As content in MOVPE grown layers is x~0.067 [10,11,12] [21,22,23]. The atomic diffusion length in these non-equilibrium processes is long enough to form crystalline lattices with uniform compositions, but short enough to avoid equilibrium phase segregation.…”

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confidence: 99%

Highly mismatched crystalline and amorphous GaN1−xAsx alloys in the whole composition range

Новиков

Broesler

et al. 2009

Journal of Applied Physics

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Alloying is a commonly accepted method to tailor properties of semiconductor materials for specific applications. Only a limited number of semiconductor alloys can be easily synthesized in the full composition range. Such alloys are, in general formed of component elements that are well matched in terms of ionicity, atom size and electronegativity. In contrast there is a broad class of potential semiconductor alloys formed of component materials with distinctly different properties. In most instances these mismatched alloys are immiscible under standard growth conditions. Here we report on the properties of GaN 1-x As x a highly mismatched, immiscible alloy system that was successfuly synthesized in the whole composition range using a non-equilibrium low temperature molecular beam epitaxy technique. The alloys are amorphous in the composition range of 0.170.2, and to the upward movement of the valence band for alloys with x<0.2. The unique features of the band structure offers an opportunity of using GaN 1-x As x alloys for various types of solar power conversion devices. 3 1. The Ga-N-As Alloy system Dilute alloysSemiconductor alloys formed through substitution of atoms with very different electronegativity and/or size have been known as highly mismatched alloys (HMAs).Because of large miscibility gaps, typically HMAs consist of a semiconductor matrix (elemental or compound) with the substitution of a small amount (up to several percents) of distinctly different isovalent atoms. The HMAs show large band gap reduction and their electronic structure is drastically different from their host materials. This is in contrast to conventional semiconductor alloys such as AlGaAs and GaAsP whose physical, electronic and optical properties can be deduced from a linear interpolation between their corresponding end point compounds with only a slight deviation, as predicted by the virtual crystal approximation (VCA). A most notable example of HMAs is the As-rich GaN x As 1-x in which strong band gap reduction by as much as 180 meV per mole percent of N has been observed [1,2,3,4]. The strong dependence of the band gap on the N content has made these diluted III-V nitrides important materials for a variety of applications, including long wavelength optoelectronic devices [5,6] and high efficiency hybrid solar cells [7,8].In contrast to the very extensively studied As-rich GaNAs alloys much less work has been devoted to HMAs on the N-rich side of this alloy system. It was found that GaN doped with As at low, impurity like levels shows a characteristic blue emission at room temperature. At higher As doping levels an abrupt decrease in the band gap of...

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“…The combined ion 3 beam and laser processing approach has been demonstrated as an effective approach to synthesize dilute semiconductor alloys including GaN x As 1-x [9,10] and Ga 1-x Mn x As [11].…”

Section: Introductionmentioning

confidence: 99%

Diluted II-VI Oxide Semiconductors with Multiple Band Gaps

et al. 2003

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We report the realization of a new multi-band-gap semiconductor. The highly mismatched alloy Zn 1-y Mn y O x Te 1-x has been synthesized using the combination of oxygen ion implantation and pulsed laser melting. Incorporation of small quantities of isovalent oxygen leads to the formation of a narrow, oxygen-derived band of extended states located within the band gap of the Zn 1-y Mn y Te host. When only 1.3% of Te atoms is replaced with oxygen in a Zn 0.88 Mn 0.12 Te crystal (with band gap of 2.32 eV) the resulting band structure consists of two direct band gaps with interband transitions at ~1.77 eV and 2.7 eV. This remarkable modification of the band structure is well described by the band anticrossing model in which the interactions between the oxygenderived band and the conduction band are considered. With multiple band gaps that fall within the solar energy spectrum, Zn 1-y Mn y O x Te 1-x is a material perfectly satisfying the conditions for single-junction photovoltaics with the potential for power conversion efficiencies surpassing 50%.PACS numbers: 71.20.Nr; 78.66.Hf; 61.72.Vv; 89.30.Cc The unusual properties of HMAs are well explained by the recently developed band anticrossing (BAC) model [3][4][5]. The model has also predicted several new effects that were later confirmed by experiments [6][7][8]. According to this model the electronic structure of the HMAs is determined by the interaction between localized states associated with N or O atoms and the extended states of the host semiconductor matrix.As a result the conduction band splits into two subbands with distinctly non-parabolic dispersion relations [3].In most instances, e.g. N in GaAs or O in CdTe, the localized states are located within the conduction band and the anticrossing interaction results in the formation of a relatively wide lower subband [5]. The subband is shifted to lower energies leading to a reduction of the energy band gap. The BAC model predicts that a narrow band can be formed only if the localized states occur well below the conduction band edge. Such a case is realized in ZnTe, MnTe and Zn 1-y Mn y Te alloys where the O level is located roughly 0.2 eV below the conduction band edge.We have shown recently that pulsed laser melting (PLM) followed by rapid thermal annealing (RTA) is well suited for the synthesis of HMAs. The combined ion 3 beam and laser processing approach has been demonstrated as an effective approach to synthesize dilute semiconductor alloys including GaN x As 1-x [9,10] and Ga 1-x Mn x As [11].Large enhancement by a factor of five in the incorporation of N in N + -implanted GaAs was observed. This is attributed to the rapid recrystallization rate associated with this process which results in the incorporation of impurity atoms to a level well above the solubility limit [12,13].Here we report the design and synthesis of a new type of material, the highly semiconductor [20,21]. Even for this non-optimal band gap configuration we calculate a power conversion efficiency of 45%, which is higher than th...

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Enhanced nitrogen incorporation by pulsed laser annealing of GaNxAs1−x formed by N ion implantation

Cited by 29 publications

References 20 publications

Synthesis of GaNxAs1−x thin films by pulsed laser melting and rapid thermal annealing of N+-implanted GaAs

Synthesis of GaNxAs1−x thin films by pulsed laser melting and rapid thermal annealing of N+-implanted GaAs

Highly mismatched crystalline and amorphous GaN1−xAsx alloys in the whole composition range

Diluted II-VI Oxide Semiconductors with Multiple Band Gaps

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