Interband and free charge carrier absorption in silicon at 800 nm: experiments and model calculations

Ndebeka, Wilfrid Innocent; Neethling, Pieter; Rohwer, Erich G.; Steenkamp, Christine M.; Bergmann, J.; Stafast, H.

doi:10.1007/s00340-017-6824-6

Cited by 5 publications

(3 citation statements)

References 18 publications

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“…The aim of the variation of the laser power and the scanning speed is to maintain the thin silicon oxide layer, so that it keeps the high passivation performance and serves as a tunneling contact. Since the absorption in the crystalline and amorphous Si for the 808 nm wavelength of the diode laser is quite low, [ 11 ] a high‐power density for liquid‐phase crystallization is required for very thin layers. As a first step, different laser powers with a scan speed of 10 mm s −1 were adjusted, the results are analyzed with scanning electron microscopy at the cross‐section of the cleaved wafers after the laser crystallization, and the SEM images are shown in Figure .…”

Section: Resultsmentioning

confidence: 99%

Diode Laser‐Crystallization for the Formation of Passivating Contacts for Solar Cells

Gawlik

Glatthaar

Dellith

et al. 2022

Physica Rapid Research Ltrs

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A new method of diode laser treatment of passivating contacts for solar cells application based on electron beam evaporated highly doped amorphous silicon (a‐Si) layers deposited on solar‐grade Czochralski wafers with SiOx tunneling layers is investigated. In a first step, an interface oxide is grown and a highly doped n‐type a‐Si layer is deposited on both sides by electron beam evaporation. In a next step, the laser treatment is applied. Two different scanning speeds of 15 and 20 mm s−1 are used. Electron backscattering diffraction and quasi‐steady‐state photo conductance measurements indicate that the a‐Si layer can be crystallized without breaking up the thin oxide layer. To determine the best parameters, the lifetime and the implied open‐circuit voltage for each laser power are measured. The first results show a fitted lifetime of 4.06 ms and an implied open‐circuit voltage up to 711 mV after a passivation step.

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Section: Resultsmentioning

confidence: 99%

Diode Laser‐Crystallization for the Formation of Passivating Contacts for Solar Cells

Gawlik

Glatthaar

Dellith

et al. 2022

Physica Rapid Research Ltrs

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“…Recently, it was also reported that ultrafast recombination together with carrier diffusion can be monitored by EFISH generated by space charge accumulation in the material. [4,17,18].…”

Section: Introductionmentioning

confidence: 99%

Ab initio nonlinear optics in solids: linear electro-optic effect and electric-field induced second-harmonic generation

Prussel

Maji

Degoli

et al. 2022

Eur. Phys. J. Spec. Top.

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HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

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“…As a result, free-carrier absorption, if its magnitude is not negligible, can compete with interband absorption and consume above-band-gap-energy photons, and the performance of solar cells will deteriorate. This is the reason why free-carrier absorption is commonly identified as a 'parasitic' absorption loss [15][16][17]. Hence, free-carrier absorption is generally believed to be one of the intrinsic physical factors responsible for solar cells unable to achieve their maximum efficiency predicted by the Shockley and Queisser (SQ) theory [18][19][20].…”

Section: Introductionmentioning

confidence: 99%

Parasitic photon process versus productive photon process: a theoretical study of free-carrier absorption in conventional and hot-carrier solar cells

Tsai

2020

J. Phys. D: Appl. Phys.

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The effects of free-carrier absorption on conventional and hot-carriers solar cells are theoretically investigated in this work. The common view that free-carrier absorption in solar cells is ‘parasitic’ is re-examined, with the assistance of a theoretical framework and formulation developed and verified for calculating free-carrier absorption coefficients. In the case of spatial partitioning with photon absorption selectivity (e.g. solar cells with embedded quantum structures), free-carrier-absorption can facilitate and enhance carrier escape processes and increases photocurrents, especially in deep potential wells. Carrier heating resulting from free-carrier absorption is shown to be extremely beneficial to hot-carrier solar cells, especially for heavily-doped wide-band-gap optical absorbers. The energy conversion processes from carrier heating of free-carrier absorption could potentially make ideal hot-carrier solar cells function like solar thermal converters. As a result, their energy conversion efficiency is closer to the thermodynamic limit, regardless of optical absorbers’ band gap energy. It is illustrated that, as an optical process which is not limited by band gap energy, free-carrier absorption could benefit possible materials of hot-carrier solar cells regardless of their band gap energy. From this perspective, free-carrier absorption is far from a ‘parasitic’ process. Its usefulness depends on how we turn it into productive work.

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Interband and free charge carrier absorption in silicon at 800 nm: experiments and model calculations

Cited by 5 publications

References 18 publications

Diode Laser‐Crystallization for the Formation of Passivating Contacts for Solar Cells

Diode Laser‐Crystallization for the Formation of Passivating Contacts for Solar Cells

Ab initio nonlinear optics in solids: linear electro-optic effect and electric-field induced second-harmonic generation

Parasitic photon process versus productive photon process: a theoretical study of free-carrier absorption in conventional and hot-carrier solar cells

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