Laser annealing of thin film polycrystalline silicon solar cell

Chowdhury, Amartya; Bahouka, Armel; Steffens, Simon; Schneider, Jens; Dore, Jonathon; Mermet, Frédéric; Slaoui, A.

doi:10.1051/epjpv/2013019

Cited by 4 publications

(11 citation statements)

References 10 publications

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“…The main target of the present work, the demonstration that D-H interdiffusion can be used for precise measurement of H diffusion length and temperature in the laser spot in (a-Si:H based) multilayer films on glass, is not affected by this inhomogeneity. Irradiation with higher homogeneity is achievable by, e.g., multiple scans with a circular Gaussian intensity profile, scans with flat-top (top hat) intensity profiles, 31 scans with line lasers, 21 or applying conventional RTP.…”

Section: Methodsmentioning

confidence: 99%

“…5,14,16,17 In these experiments, however, the decrease in H concentration overlapped with the increase in crystallinity so that no a-Si:H with reduced H concentration was identified. With regard to defect reduction/device improvement by laser annealing, only a few reports have been published like studies by Lee et al 20 and Chowdhury et al 21 who indeed found improvement of amorphous and polycrystalline silicon based devices by laser treatment. One reason for the limited application may be the lack of knowledge of the precise temperature as in practice the absolute temperature for RTP is often unknown 22 and the effort to measure the RTP temperature accurately by conventional methods (like thermal imaging camera, 21 pyrometer, 23 or thermocouple 24 ) is clearly high.…”

Section: Introductionmentioning

confidence: 99%

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Temperature and hydrogen diffusion length in hydrogenated amorphous silicon films on glass while scanning with a continuous wave laser at 532 nm wavelength

Beyer

Andrä

Bergmann

et al. 2018

Journal of Applied Physics

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Rapid thermal annealing by, e.g., laser scanning of hydrogenated amorphous silicon (a-Si:H) films is of interest for device improvement and for development of new device structures for solar cell and large area display application. For well controlled annealing of such multilayers, precise knowledge of temperature and/or hydrogen diffusion length in the heated material is required but unavailable so far. In this study, we explore the use of deuterium (D) and hydrogen (H) interdiffusion during laser scanning (employing a continuous wave laser at 532 nm wavelength) to characterize both quantities. The evaluation of temperature from hydrogen diffusion data requires knowledge of the high temperature (T > 500 °C) deuterium-hydrogen (D-H) interdiffusion Arrhenius parameters for which, however, no experimental data exist. Using data based on recent model considerations, we find for laser scanning of single films on glass substrates a broad scale agreement with experimental temperature data obtained by measuring the silicon melting point and with calculated data using a physical model as well as published work. Since D-H interdiffusion measures hydrogen diffusion length and temperature within the silicon films by a memory effect, the method is capable of determining both quantities precisely also in multilayer structures, as is demonstrated for films underneath metal contacts. Several applications are discussed. Employing literature data of laser-induced temperature rise, laser scanning is used to measure the H diffusion coefficient at T > 500 °C in a-Si:H. The model-based high temperature hydrogen diffusion parameters are confirmed with important implications for the understanding of hydrogen diffusion in the amorphous silicon material.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Temperature and hydrogen diffusion length in hydrogenated amorphous silicon films on glass while scanning with a continuous wave laser at 532 nm wavelength

Beyer

Andrä

Bergmann

et al. 2018

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…13,20,22 Moreover, the defects and deformations of the substrates can be avoided or lowered and the choice of substrates and IDLs (buffer layers) can be diversified. 12,16,19,21,23,24 The LC method for crystallization of a-Si thin films was studied with CW diode lasers with a line-focus in which the axis of the line-focus was perpendicular to scan directions. 24,25 Most of the past work was carried out using CW infrared (IR) lasers, and a-Si films on glass substrates were kept at elevated temperatures during the laser annealing process because at room temperature the a-Si layers exhibit low absorption of the infrared irradiation in comparison to the visible.…”

Section: Introductionmentioning

confidence: 99%

“…12,16,19,21,23,24 The LC method for crystallization of a-Si thin films was studied with CW diode lasers with a line-focus in which the axis of the line-focus was perpendicular to scan directions. 24,25 Most of the past work was carried out using CW infrared (IR) lasers, and a-Si films on glass substrates were kept at elevated temperatures during the laser annealing process because at room temperature the a-Si layers exhibit low absorption of the infrared irradiation in comparison to the visible. 5,24 To increase the light absorption, the samples were kept at temperatures in the range of 400–700 °C.…”

Section: Introductionmentioning

confidence: 99%

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Improvement of Laser-Crystallized Silicon Film Quality via Intermediate Dielectric Layers on a Glass Substrate

2018

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The laser crystallization (LC) of amorphous silicon thin films into polycrystalline silicon (pc-Si) thin films on glass substrates is an active field of research in the fabrication of Si-based thin film transistors and thin film solar cells. Efforts have been, in particular, focused on the improvement of LC technique. Adhesion promoters of the crystallized Si thin films at the glass interface play a crucial role in the stability and device performance of fabricated structures. The crystalline Si thin films are required to be produced free of contamination risks arising from impurity diffusion from the glass substrate. Moreover, it is preferable to fabricate pc-Si thin films at temperatures as close as possible to the ambient temperature for an effective cost reduction. In this work, we demonstrate the successful use of a commercially available nanosecond pulsed laser marker at 1064 nm wavelength for Si crystallization at ambient conditions compared to the common method of pre-elevated substrate temperatures used in continuous wave laser irradiation technique. As a result, our technique results in a better energy balance than that in previous works. The second main purpose of this study is to enhance the crystallinity of Si thin films and to determine the best choice of an intermediate dielectric layer (IDL) comparatively among four thin buffer layers, namely, SiN x , SiO 2 , ZnO, and TiO 2 , for the sake of obtaining improved adhesion and larger crystalline domains as compared to that on a direct Si–glass interface. The crystalline qualities of samples containing IDLs of SiN x , SiO 2 , ZnO, and TiO 2 were compared via Raman spectroscopy analysis and electron backscatter diffraction method against the direct Si–glass interface reference. The analyses quantitatively showed that both the crystallinity and the domain sizes can be increased via IDLs.

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Revealing Laser Crystallization Mechanism of Silicon Thin Films via Pulsed IR Lasers

2019

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Pulsed laser absorption-mediated explosive crystallization of silicon films has extensively been studied using microscopy techniques on single laser pulse-irradiated regions in the literature. In this work, we experimentally demonstrate and theoretically explain in detail the use of slow quenching regime for laser crystallization mediated by highly overlapping pulses. Increasing the use of Si in thin film transistors and photovoltaic applications drives researchers to find cost-effective and efficient ways of manufacturing crystalline Si films on various types of substrates. Understanding the mechanism of the laser crystallization process of Si films by pulsed lasers becomes crucial. This work reveals the laser crystallization mechanism of Si thin films in macroscopic scales by considering heat transfer and accumulation dynamics. Our motivation is to describe the dynamics of the laser crystallization of Si films to provide a complementary guide for the production of device-grade c-Si films by infrared pulsed laser without employing preheated substrates. c-Si grains exceeding 2 mm in size were formed by laser crystallization of 1 μm-thick Si films without any pre/ postannealing step at room temperature and within a typical continuous wave irradiation-based light energy budget, which we think to be the most important achievement of our work.

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Laser annealing of thin film polycrystalline silicon solar cell

Cited by 4 publications

References 10 publications

Temperature and hydrogen diffusion length in hydrogenated amorphous silicon films on glass while scanning with a continuous wave laser at 532 nm wavelength

Temperature and hydrogen diffusion length in hydrogenated amorphous silicon films on glass while scanning with a continuous wave laser at 532 nm wavelength

Improvement of Laser-Crystallized Silicon Film Quality via Intermediate Dielectric Layers on a Glass Substrate

Revealing Laser Crystallization Mechanism of Silicon Thin Films via Pulsed IR Lasers

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