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Hasselt, Belgium

Gall S.,French National Solar Energy Institute | Manuel S.,French National Solar Energy Institute | Lerat J.-F.,EXCICO Group NV
Energy Procedia | Year: 2013

A new doping process is investigated by using Excimer Laser Annealing (ELA) on various Atomic Layer Deposition (ALD)-Al2O3/PECVD- SiNx(B) passivation stack. In a first part the passivation quality of dielectric stacks is investigated on lowly doped p-type Si substrate. Similar passivation level is highlighted with Boron containing SiNx as compared to un-doped SiNx layer when a thin interfacial Al 2O3 layer is first deposited on silicon. In a second part laser doping of the silicon substrate is highlighted by sheet resistance (R sh) decrease. Pulse energy and pulse number influence the diffusion of Boron and Aluminum atoms from the dielectric stack into the silicon. Electro Chemical Voltage (ECV) profiles confirmed p+ region formation. XPS analysis confirmed the presence of both doping atoms in the p+ region. It is suggested that Al is rather bonded to N and O than to Si atoms while B plays a major role in the doping mechanism of the Si lattice. © 2013 The Authors.

Johnson E.V.,Ecole Polytechnique - Palaiseau | Prodhomme P.,Total S.A. | Boniface C.,EXCICO France SAS | Huet K.,EXCICO France SAS | And 2 more authors.
Solar Energy Materials and Solar Cells | Year: 2011

We demonstrate the effect of excimer (XeCl=308 nm) laser annealing on thin films of ZnO:Al deposited by RF sputtering at room temperature. The as-deposited films have good sheet resistance (<11 Ω/□) but poor transparency, and a subsequent chemical etching step using dilute HCl to texture the film surface results in a level of haze ineffective for light-trapping in thin film photovoltaic cells. Excimer laser annealing at the optimized fluence (single pulses of 0.50.7 J/cm2) improves the film transparency, particularly through a blue-shift in the band-gap, without significantly impacting the conductivity. More importantly, chemical etching of these laser annealed films results in textured films with controllable spectral distributions of haze. We demonstrate the enhanced optical properties (transmission and haze) after laser annealing and etching the ZnO:Al films through the fabrication of hydrogenated microcrystalline silicon pin solar cells, and show a significant improvement in the photocurrent density (up to 2.2 mA/cm2) for the optimally annealed substrates - particularly at wavelengths greater than 600 nm (up to 1.7 mA/cm2) where light-trapping is important. © 2011 Elsevier B.V. All rights reserved.

A method for fabricating a photovoltaic device, including depositing a TCO-layer on a substrate and annealing the TCO layer by laser irradiation having irradiation parameters, wherein the irradiation parameters are selected such that the annealing includes increasing the haze % of the TCO layer compared to the as deposited TCO layer. Additionally, a TCO layer having a haze % of at least 2% in the visible light wavelength range and a surface roughness of less than 0 nanometer RMS, and a photovoltaic device including such TCO-layer.

Imec, K.U.Leuven R&D and Excico Group NV | Date: 2012-11-23

The present invention is related to a method for forming a metal silicide layer on a textured silicon substrate surface. The method includes providing a metal layer on a textured silicon substrate and performing a pulsed laser annealing step providing at least one UV laser pulse with a laser fluence in the range between

Gall S.,French National Solar Energy Institute | Paviet-Salomon B.,French National Solar Energy Institute | Lerat J.,EXCICO Group NV | Emeraud T.,EXCICO Group NV
Energy Procedia | Year: 2012

In this paper an Excimer laser doping process is investigated from SiN:P and SiN:B PECVD layers used as dopant sources. It is demonstrated efficient doping effect with P and B with large doping range on both p+ and n+ prediffused regions. Doped regions are shown to be modified in term of surface concentration and depth by both laserdriven re-distribution and additional over-doping from doped dielectric source. When using laser doping from SiN:B layer, partial or complete compensation of the initial n+ emitter is highlighted. Moreover similar study with SiN:P demonstrated the potential for over-compensate the initial p+ emitter. These laser processes could be used for realization of adjacent p+ and n + regions with controlled profiles. Moreover fluence ranges where material could be fully compensated are pointed.

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