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Nanomanufacturing: ALD4PV


Program ALD4PV Workshop

Date: Thursday 20 March 2014
Location: De Zwarte Doos (Filmzaal/Lounge)
Eindhoven University of Technology

A pdf version for printing can be found here.

Please click on the title or the abstract to view the presentation if available.

8:30-9.00 Registration & coffee
Opening and introduction
9:00-9:10 picture Dr. Diana Garcia-Alonso – Eindhoven University of Technology (NL)
9:10-9:30 picture Prof. Erwin Kessels – Eindhoven University of Technology (NL)
Introduction to ALD
Crystalline silicon and heterojunction solar cells
9:30-10:15 picture Dr. Joachim John (or co-worker) – IMEC (B)
Passivation of next generation Silicon solar cells using ALD AlOx
The next generation silicon solar cells are finding their way from the pilot lines to the production lines. This concepts using passivated emitter and rear cell structures  (PERC) or passivated emitter and rear totally diffused cell structures (PERT), require a passivation scheme that fulfil the need of solar cell industry: high throughput solar cell production, high passivation performance, low cost of ownership. AlOx applied by atomic layer deposition seems to be an excellent candidate to fulfil this requirements and is being implemented as passivation layer in next generation silicon solar cells.
10:15-10:35 picture Sjoerd Smit – Eindhoven University of Technology (NL)
ALD as an enabling technology for new c-Silicon solar cell concepts
The excellent growth control that ALD offers for the deposition of thin films opens up new possibilities for the design of c-Si solar cells. In this presentation, examples will be given of such new concepts. Key advantages of ALD will be explained, such as conformality, high thickness control and high precision (graded) doping of conductive oxides. The industrial potential of ALD will be addressed as well.
10:35-11:05 Coffee break
CIGS solar cells
11:05-11:50 picture Dr. Tobias Törndahl – Uppsala University (SE)
Alternative buffer layers by ALD for CuIn1-xGaxSe2 solar cells
Introduction to CIGS solar cells and currently available buffer layer systems. Growth of ZnO-based compounds such as ZnO1-xSx, Zn1-xMgxO and Zn1-xSnxOy on CIGS by atomic layer deposition. Material characterization and solar cell electrical performance of the different buffer layer systems.
11:50-12:10 picture Dr. Harm Knoops – Eindhoven University of Technology (NL)
ALD of Resistive i-ZnO and Conductive Doped ZnO for CIGS
Thermal ALD of ZnO is a relatively fast process due to the high-vapor pressure precursors DEZ and H2O. Besides being considered for depositing the buffer layer in the CIGS cell, ALD also has potential for the resistive i-ZnO and conductive doped ZnO layer. This contribution will discuss the requirements, material properties, and initial results regarding the potential and application of ZnO-based layers for CIGS.
12:10-12:30 picture Dr. Bart Vermang – Uppsala University (SE)
Development of rear surface passivated Cu(In,Ga)Se2 solar cells
Rear surface passivation as used in advanced silicon solar cell concepts is developed for CIGSe thin film solar cells. The new cell design reduces rear surface recombination by combining a rear surface passivation layer and nano-sized local point contacts. Atomic layer deposition of Al2O3 is used to passivate the CIGS rear surface and the formation of nanosphere-shaped precipitates in chemical bath deposition of CdS to generate point contact openings.
12:30-14:00 Lunch break sponsored by Pffeiffer Vacuum
DSC solar cells and beyond
14:00-14:45 picture Dr. Alex Martinson – Argonne National Lab (US)
Squeezing heterogeneity out of wide gap oxide surfaces: An ALD approach
The dependence of electron transfer (ET) on TiO2 surface properties (structure, defects, and facets) remains poorly understood due to the difficulties of deconvoluting the signal from a multitude of surface binding sites in highly heterogeneous ET systems. In an effort to correlate TiO2 surface features with ET, we examine the photoinduced ET dynamics from single quantum dots to polycrystalline TiO2 thin films  grown by atomic layer deposition (ALD). Further modification with a submonolayer of Al2O3  (also by ALD) enables the selective exclusion of the more rapid ET pathway. 
14:45-15:05 picture Dr. Valerio Zardetto – Eindhoven University of Technology (NL)
Low temperature ALD for flexible DSC
Low temperature processing by plasma-assisted atomic layer deposition (PA-ALD) is a valid candidate for the deposition of metal nanoparticles (NPs) and metal oxides  used in flexible dye sensitized solar cells (DSCs). The synthesis of platinum NPs has been successfully applied to achieve highly transparent plastic DSC counter-electrode. Furthermore ultrathin Al2O3 and TiO2 compact layers were investigated to decrease the recombination processes at the interface between the PEN/ITO substrate and the mediator (liquid electrolyte or organic material), especially at low light intensity.
15:05-15:25 picture Dr. Nicolas Tétreault – École Polytechnique Fédérale Lausanne (CH)
From tunneling layers to 3D host-guest nanostructures: ALD role in dye-sensitized solar cells
Dye-sensitized solar cells (DSCs) are based on complex photo-electrochemistry taking place within a high aspect ratio and surface area semiconductor. In our quest for new concepts on DSCs, ALD is a tool that enables unprecedented freedom to modify the cell. From wide bandgap metal oxide tunneling layers to more complex 3D host-guest nanostructures, ALD has found itself to be indispensable in a foreign field of research.
15:25-16:00 Coffee break
Upscaling of ALD
16:00-16:45 picture Dr. Ernst Granneman – Levitech (NL)
Implementation of ALD Al2O3 films on an industrial scale
Al2O3 films are in the process of being implemented in high-volume manufacturing of solar cells. Currently, most emphasis is on p-type PERC cells. The two most important technologies that are competing are PECVD and ALD. An overview of the various ALD approaches will be given, followed by details on the Levitrack spatial ALD system. The process will be discussed as well as recent results on solar cells.
16:45-17:00 Closure

17:00-18:00 Drinks sponsored by NEVAC
Networking and lab tour