Effect of H<sub>2</sub>-dilution in Si-cap formation on photoluminescence intensity of Si quantum dots with Ge core

Fujimori, Shuntaro; Nagai, Ryo; Ikeda, Mitsuhisa; Makihara, Katsunori; Miyazaki, Seiichi

doi:10.7567/1347-4065/ab0c7a

Cited by 2 publications

(2 citation statements)

References 30 publications

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“…In a different approach, hydrogen passivation can be employed to saturate the dangling bonds from unwanted defects in the Si matrix. This method is widely used in applications ranging from solar cells to CMOS technology to emission improvement of GeSi nanostructures [203,204,205]. In Figure 11, we compare the PL emission for a series of DEQD samples that underwent various lowenergy proton irradiation treatment with different irradiation doses (5×10 17 cm −2 , 1×10 18 cm −2 , and 5×10 18 cm −2 ) to a DEQD reference sample (black spectra in Fig.…”

Section: Curing and Passivation Of Non-radiative Recombination Centersmentioning

confidence: 99%

Light-Emission from Ion-Implanted Group-IV Nanostructures

Brehm

2021

Topics in Applied Physics

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Silicon photonics is destined to revolutionize technological areas, such as short-distance data transfer and sensing applications by combining the benefits of integrated optics with the assertiveness of siliconbased microelectronics. However, the lack of practical and low-cost silicon-based monolithic light sources such as light-emitting diodes and, in particular, lasers is the main bottleneck for silicon photonics to become the key technology of the 21 st century. After briefly reviewing the state of the art regarding silicon-based light-emitters, we discuss the challenges and benefits of a highly flexible approach: The epitaxial incorporation of group-IV nanostructures into crystalline silicon. We argue that a paradigm change for group-IV quantum dots (QDs) can be achieved by the intentional incorporation of extended point defects inside the QDs upon low energy ion implantation. The superior light-emission properties from such defect-enhanced quantum dots (DEQDs), our present understanding of their structural formation and light-emission mechanisms will be discussed. We will show that useful electrically-driven devices, such as light-emitting diodes (LEDs) can be fabricated employing optically active DEQDmaterial. These LEDs exhibit exceptional temperature-stability of their light emission properties even up to 100°C, unprecedented for purely group-IV-based optoelectronic devices. Thereafter, we will assess the superior temperature stability of the structural properties of DEQDs upon thermal annealing, the scalability of the light-emission with the DEQD density and passivation schemes to further improve the optical properties. The chapter ends with a discussion of future research directions that will spark the development of this exciting field even further.

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Section: Curing and Passivation Of Non-radiative Recombination Centersmentioning

confidence: 99%

Light-Emission from Ion-Implanted Group-IV Nanostructures

Brehm

2021

Topics in Applied Physics

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“…Nevertheless, point defects might still limit the PL yield of DEQDs by the non-intentional introduction of non-radiative recombination paths in the Si matrix. Hydrogen passivation is an indispensable tool for improving the electrical and optical quality of silicon in applications ranging from solar cells to CMOS technology to emission improvement of GeSi nanostructures [23,43,44]. DEQDs-the optically active material in this work-are surrounded by crystalline Si; the Si float-zone substrate, and the epitaxial Si buffer and capping layers.…”

Section: H-irradiation Treatment Of Deqdsmentioning

confidence: 99%

In-Situ Annealing and Hydrogen Irradiation of Defect-Enhanced Germanium Quantum Dot Light Sources on Silicon

et al. 2020

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While light-emitting nanostructures composed of group-IV materials fulfil the mandatory compatibility with CMOS-fabrication methods, factors such as the structural stability of the nanostructures upon thermal annealing, and the ensuing photoluminescence (PL) emission properties, are of key relevance. In addition, the possibility of improving the PL efficiency by suitable post-growth treatments, such as hydrogen irradiation, is important too. We address these issues for self-assembled Ge quantum dots (QDs) that are co-implanted with Ge ions during their epitaxial growth. The presence of defects introduced by the impinging Ge ions results in pronounced PL-emission at telecom wavelengths up to room temperature (RT) and above. This approach allows us to overcome the severe limitations of light generation in the indirect-band-gap group-IV materials. By performing in-situ annealing, we demonstrate a high PL-stability of the defect-enhanced QD (DEQD) system against thermal treatment up to 600 °C for at least 2 h, even though the Ge QDs are structurally affected by Si/Ge intermixing via bulk diffusion. The latter, in turn, allows for emission tuning of the DEQDs over the entire telecom wavelength range from 1.3 µm to 1.55 µm. Two quenching mechanisms for light-emission are discussed; first, luminescence quenching at high PL recording temperatures, associated with the thermal escape of holes to the surrounding wetting layer; and second, annealing-induced PL-quenching at annealing temperatures >650 °C, which is associated with a migration of the defect complex out of the QD. We show that low-energy ex-situ proton irradiation into the Si matrix further improves the light emission properties of the DEQDs, whereas proton irradiation-related optically active G-centers do not affect the room temperature luminescence properties of DEQDs.

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Effect of H₂-dilution in Si-cap formation on photoluminescence intensity of Si quantum dots with Ge core

Cited by 2 publications

References 30 publications

Light-Emission from Ion-Implanted Group-IV Nanostructures

Light-Emission from Ion-Implanted Group-IV Nanostructures

In-Situ Annealing and Hydrogen Irradiation of Defect-Enhanced Germanium Quantum Dot Light Sources on Silicon

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Effect of H2-dilution in Si-cap formation on photoluminescence intensity of Si quantum dots with Ge core

Cited by 2 publications

References 30 publications

Light-Emission from Ion-Implanted Group-IV Nanostructures

Light-Emission from Ion-Implanted Group-IV Nanostructures

In-Situ Annealing and Hydrogen Irradiation of Defect-Enhanced Germanium Quantum Dot Light Sources on Silicon

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Effect of H₂-dilution in Si-cap formation on photoluminescence intensity of Si quantum dots with Ge core