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Three-dimensional (3D) thin-film solid-state batteries are an interesting concept for microstorage, promising high footprint capacity, fast charging, safety, and long lifetime. However, to realize their commercialization, several challenges still need to be overcome. In this work, we focus on two issues: the conformal coating and the high throughput deposition of thin-film layers. First, to facilitate conformal deposition, a design based on 3D micropillars is chosen. Although such a design has been suggested in the past, we calculate for the first time what (footprint) capacities can be expected when using fully optimized pillar geometries while taking practical manufacturability into consideration. Next, spatial atomic layer deposition (S-ALD) is investigated as a scalable and conformal deposition technique. As proof-of-concept, 100 nm Cl-doped am-TiO 2 thin-film electrodes are deposited by S-ALD on TiN-coated silicon micropillars. The influence of deposition parameters (i.e., exposure time and temperature) on the conformality and uniformity across the micropillar substrate is investigated. The results are discussed in terms of precursor diffusion and depletion, which is supported by an analytical model developed for our micropillar array. Furthermore, the Li-ion insertion properties of 3D electrodes fabricated by S-ALD and conventional ALD are compared. This research highlights the challenges and promises of 3D microbatteries and guides future S-ALD development to enable conformal and high-throughput thin-film deposition.

The purpose of the work is to investigate high-efficient and stable 4-terminal perovskite/c-Si tandem devices. Hybrid tandems of c-Si bottom cells and perovskite top cells are perhaps the most promising candidates to reduce the levelized cost of electricity by increasing the overall tandem cell efficiency. To turn this promise in a commercial success, perovskite/c-Si tandem devices need to fulfill at least the following requirements: matching lifetimes between the perovskite top cell and the bottom c-Si cell, i.e. 25 years; high near-infrared transparency of top cell, scalable process steps and low cost of materials

We present recent developments on flexible a-IGZO TFT technology scaling in terms of TFT channel length and operating voltage, as well as manufacturing cost optimization with a focus on R2R processing compatibility. We present progress on the relevant technology building blocks; (i) R2R compatible TFT architecture, (ii) (multilevel) nanoimprint lithography and (iii) S-ALD deposited TFT materials. Additionally, we show a developing application that drives scaling of the technology, namely a monolithically integrated flexible AMOLED display with in-display fingerprint detection. © 2018 FTFMD. International Society of Functional Thin Film Materials and Devices; The Japan Society of Applied Physics

We present a thin-film dual-layer bottom barrier on polyimide that is compatible with 350°C backplane processing for organic light-emitting diode displays and that can facilitate foldable active-matrix organic light-emitting diode devices with a bending radius of

Atomic layer deposition by means of spatial separation of reactive gases is emerging as an industrial manufacturing technology. Integration of non-thermal plasma in spatial ALD machines will further expand the process window towards lower operation temperatures and specific materials requiring radicals (O, N, H, OH, NH etc.). Plasma sources with exceptional dimensional and chemical stability providing flow geometries optimized for efficient radical transport are needed. This paper reports on the initial steps taken to provide and examine the required linear scalable plasma sources. The effectiveness of close-proximity direct and remote plasma sources are demonstrated using thin film deposition of Al2O3 and ZrO2. Paper received the Hans Pulker Award for the best conference paper.

In this manuscript we present the first successful application of a spatial atomic-layer-deposition process to thin film solar cells. Zn(O,S) has been grown by spatial atomic layer deposition (S-ALD) at atmospheric pressure and applied as buffer layer in rigid and flexible CIGS cells by a lab-scale (15×15 cm2) S-ALD set-up. We achieved values of cell efficiency (16 %) higher than the reference cells on glass substrate. © 2017 IEEE. Newport

The industrial need for high-throughput and low-cost ZnO deposition processes has triggered the development of atmospheric vapor-phase deposition techniques which can be easily applied to continuous, in-line manufacturing. While atmospheric CVD is a mature technology, new processes for the growth of transparent conductive oxides on thermally sensitive materials or flexible substrates are being developed, such as atmospheric plasma-enhanced (PE)-CVD and atmospheric spatial atomic layer deposition (ALD). In this article, the challenges and recent results on the growth of ZnO under atmospheric pressure by CVD, PE-CVD, and spatial ALD are reviewed and the use of these films as transparent electrodes in thin film solar cells are presented.

Conventional Deep Reactive Ion Etching (DRIE) is a plasma etch process with alternating half-cycles of 1) Si-etching with SF6 to form gaseous SiFx etch products, and 2) passivation with C4F8 polymerizing as a protecting fluorocarbon deposit on the sidewalls and bottom of the etched features. We report on a novel alternative and disruptive technology concept of Spatially-divided Deep Reactive Ion Etching, where the process is converted from the time-divided into the spatially divided regime. The spatial division can be accomplished by ~20 to 100 μm high inert gas-bearing ‘curtains’ that confine the reactive gases to individual (often linear) injection slots constructed in a gas injector head. By horizontally moving the substrate back and forth under the head one can realize the alternate exposures to compose the overall cycle.Next improvement in the spatially-divided approach is the replacement of the CVD-based C4F8 passivation steps by ALD-based oxide (e.g. SiO2) deposition cycles. The method can have industrial potential in cost-effective creation of advanced 3D TSV interconnects and MEMS, but also in advanced patterning of, e.g., nanoscale FinFET devices with reduced line edge roughness, thus approaching Atomic Layer Etching accuracy.

Undoped and indium doped ZnO films have been grown by Spatial Atomic Layer Deposition at atmospheric pressure. The electrical properties of ZnO films are controlled by varying the indium content in the range from 0 to 15 %. A minimum resistivity value of 3 mΩ•cm is measured in 180 nm thick films for In/(In+Zn) ratio equal to 6 %, corresponding to a majority carrier density of 6•1020 cm-3 and a mobility of 3 cm2/Vs. All the films are highly transparent (> 80 %) in the visible range. cop. The Electrochemical Society.

28th European Photovoltaic Solar Energy Conference and Exhibition; 2414-2417, ZnO films have been grown on a moving glass substrate by high temperature (480 0C) chemical vapour deposition (CVD) and low temperature (200 0C) plasma enhanced CVD (PE-CVD) process at atmospheric pressure. Deposition rates above 7 nm/s have been achieved for substrate speeds from 20 to 500 mm/min. The conductivity of the films is enhanced by Al doping of CVD ZnO or by exposure to near-UV radiation of PE-CVD ZnO. Both CVD ZnO:Al and UV-exposed PE-CVD i-ZnO films are highly transparent (> 85% in the visible range) and conductive (< 15 Ohm/sq for a thickness above 1200 nm). ZnO:Al has been used as front electrode in amorphous silicon (a-Si:H) solar cells while i-ZnO has been applied as electrode in CIGS solar cells, achieving an efficiency of 8% and 15.4%, respectively.

Undoped zinc oxide (ZnO) films have been grown on a moving glass substrate by plasma-enhanced chemical vapor deposition at atmospheric pressure. High deposition rates of ∼7 nm/s are achieved at low temperature (200°C) for a substrate speed from 20 to 60 mm/min. ZnO films are highly transparent in the visible range (90%). By a short (∼minute) post-deposition exposure to near-ultraviolet light, a very low resistivity value of 1.6·10 -3 Ω cm for undoped ZnO is achieved, which is independent on the film thickness in the range from 180 to 1200 nm. The photo-enhanced conductivity is stable in time at room temperature when ZnO is coated by an Al2O3 barrier film, deposited by the industrially scalable spatial atomic layer deposition technique. ZnO and Al2O3 films have been used as front electrode and barrier, respectively, in Cu(In,Ga)Se2 (CIGS) solar cells. An average efficiency of 15.4 ± 0.2% (15 cells) is obtained that is similar to the efficiency of CIGS reference cells in which sputtered ZnO:Al is used as electrode. Copyright © 2013 John Wiley & Sons, Ltd. Undoped zinc oxide (ZnO) has been grown by plasma-enhanced chemical vapor deposition at atmospheric pressure. After post-deposition exposure to near-ultraviolet light, a low value of resistance (15 Ω/sq) is achieved in films that are highly transparent (90 %) in the visible range. ZnO is used as front electrode in Cu(InGa)Se2 solar cells achieving an efficiency of 15.4%, similar to reference cells with a sputtered Al:ZnO electrode. Copyright © 2013 John Wiley & Sons, Ltd.

In this work we will review our recent work on novel alternative and disruptive technology concepts with industrial potential for cost-effective and high-speed interconnect manufacturing, in particular on the creation (drilling and filling) of advanced interconnects like TSVs. These technologies are 1) Spatially-divided Deep Reactive Ion Etching, S-DRIE, 2) Electrochemical Micromachining, ECM, and 3) Laser-Induced Forward Transfer, LIFT. The first technique will be reviewed in detail, the other two will only shortly be described.

27th European Photovoltaic Solar Energy Conference and Exhibition; 2290-2293, Zinc oxide thin films have been deposited at high growth rates (up to ~ 1 nm/s) by spatial atomic layer deposition technique at atmospheric pressure. Water has been used as oxidant for diethylzinc (DEZ) at deposition temperature of 250°C. By varying the DEZ partial pressure, the electrical properties of ZnO can be controlled, ranging from heavily n-type conductive (with 4 mOhm.cm resistivity for 250 nm thickness) to insulating. All the films have c-axis (100) preferential orientation, good crystalline quality and high transparency (~ 85%) in the visible range. Combining the high deposition rates with a precise control of functional properties (i.e. conductivity and transparency) of the films, the industrially scalable spatial ALD technique can become a disruptive manufacturing method for the ZnO-based industry. Currently, we are developing a plasma enhanced chemical vapor deposition process for the growth of ZnO thin films at atmospheric pressure and low temperature (200°C).

A next generation material for surface passivation of crystalline Si is Al2O3. It has been shown that both thermal and plasma-assisted (PA) atomic layer deposition (ALD) Al2O3 provide an adequate level of surface passivation for both p-and n-type Si substrates. However, conventional time-resolved ALD is limited by its low deposition rate. Therefore, an experimental high-deposition-rate prototype ALD reactor based on the spatially separated ALD principle has been developed and Al2O3 deposition rates up to 1.2 nm/s have been demonstrated. In this work, the passivation quality and uniformity of the experimental spatially separated ALD Al2O3 films are evaluated and compared to conventional temporal ALD Al2O3, by use of quasi-steady-state photo-conductance (QSSPC) and carrier density imaging (CDI). It is shown that spatially separated Al2O3 films of increasing thickness provide an increasing surface passivation level. Moreover, on p-type CZ Si, 10 and 30nm spatial ALD Al2O3 layers can achieve the same level of surface passivation as equivalent temporal ALD Al2O3 layers. In contrast, on n-type FZ Si, spatially separated ALD Al2O3 samples generally do not reach the same optimal passivation quality as equivalent conventional temporal ALD Al 2O3 samples. Nevertheless, after "firing", 30 nm of spatially separated ALD Al2O3 on 250mm thick n-type (2.4Vcm) FZ Si wafers can lead to effective surface recombination velocities as low as 2.9 cm/s, compared to 1.9 cm/s in the case of 30nm of temporal ALD Al2O3.

An atmospheric pressure plasma enhanced atomic layer deposition reactor has been developed, to deposit Al2O3 films from trimethyl aluminum and an He/O2 plasma. This technique can be used for 2D patterned deposition in a single in-line process by making use of switched localized plasma sources. It was observed that the sharpness of the patterns is primarily influenced by the concentration of reactive plasma species and by the dimensions of the plasma source.

26th European Photovoltaic Solar Energy Conference and Exhibition; 2998-3000, A comparison of various transparent conducting materials based on their transparency versus sheet resistance characteristics is presented. Transparent conducting oxides (TCOs) are still superior in performance compared to various recent alternatives and can only be surpassed by the combination of TCOs with a metal grid. Results on modeling and design optimization are presented using a monolithically integrated CIGS cell configuration as case. This study showed that considerable efficiency enhancement (17% in power output) can be achieved for metal grid TCO combinations compared to single TCOs. Conductivity improvement has been experimentally verified on both commercial ITO PET foil as well as on ZnO coated glass with electrochemically deposited metal grids. Conductivities below 0,1 Ohm/sq were reached and 80 times and 400 times conductivity improvements were obtained at a transparency loss of only 3% and 6%, respectively. It was also found that electrochemical deposition results in more conductive and more transparent grids than obtained by Ag-ink screen printing.

25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 1130-1133, We present independently confirmed efficiencies of 21.4% for PERC cells with plasma-assisted atomic- layer-deposited (plasma ALD) Al2O3 rear passivation and 20.7% for cells with thermal ALD-Al2O3. Additionally, we evaluate three different industrially relevant techniques for the deposition of surface-passivating Al2O3 layers on 1- Ωcm p-type silicon wafers, namely high-rate spatial ALD (spatial ALD), plasma-enhanced chemical vapour deposition (PECVD) and reactive sputtering. Using spatial ALD and PECVD, surface recombination velocities (SRVs) below 10 cm/s are obtained. Sputtered Al2O3 layers still provide an SRV of 35 – 70 cm/s. Despite their lower passivation quality compared to the Al2O3 films deposited by spatial ALD and by PECVD, we demonstrate that the sputtered Al2O3 layers are still suitable for the fabrication of 20.1% efficient PERC cells. After firing at ~800°C in a conveyorbelt furnace the SRV provided by the Al2O3 films deposited by spatial ALD is still below 20 cm/s, indicating an excellent firing stability. Both PECVD and sputtered Al2O3 passivation layers degrade to SRVs larger than 100 cm/s after firing. Hence, the firing stability of PECVD and – in particular – sputtered Al2O3 needs further optimisation.

25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 1110-1113, A next generat ion material for surface passivat ion is atomic layer deposit ion (ALD) Al2O3. However, convent ional t ime-resolved ALD is limited by its low deposit ion rate. Therefore, an experimental high - deposit ion-rate prototype ALD reactor based on the spat ially-separated ALD principle has been developed. This reactor leads to deposit ion rates up to 1.2 nm Al2O3/s. In this work, the passivat ion quality and uniformity of the experimental spat ially-separated ALD Al2O3 films are evaluated and compared to convent ional temporal ALD Al2O3, by use of quasi-steady-state photo-conductance (QSSPC) and carrier density imaging (CDI). It is shown that spat ially-separated Al2O3 films of increasing thickness provide an increasing surface passivat ion level. Moreover, on p-type CZ Si, 10 and 30 nm spat ial ALD Al2O3 layers can achieve the same level of surface passivat ion as equivalent temporal ALD Al2O3 layers. In cont rast , on n-type FZ Si, spat ially-separated ALD Al2O3 samples generally do not reach the same opt imal passivat ion quality as equivalent convent ional temporal ALD Al2O3 samples. Nevert heless, aft er “ firing”, 30 nm of spat ially -separated ALD Al2O3 on 250 μm t hick n-type (1-5 Ω.cm) FZ Si wafers can lead t o effect ive surface recombinat ion velocit ies as low as 2.9 cm/s, compared t o 1.9 cm/s in the case of 30 nm of temporal ALD Al2O3.

The next generation of industrial silicon solar cells aims at efficiencies of 20% and above. To achieve this goal using ever-thinner silicon wafers, a highly effective surface passivation of the cell front and rear is required. In the past, finding a suitable dielectric layer providing a high-quality rear passivation has been a major challenge. Aluminium oxide (Al2O3) grown by atomic layer deposition (ALD) has only recently turned out to be a nearly perfect candidate for such a dielectric. However, conventional ALD is limited to deposition rates well below 2nm/min, which is incompatible with industrial solar cell production. This paper assesses the passivation quality provided by three different industrially relevant techniques for the deposition of Al2O3 layers, namely high-rate spatial ALD, plasma-enhanced chemical vapour deposition (PECVD) and reactive sputtering.

25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 641-643, A vital part in thin film solar cells is the transparent conductive layer. Highly conductive TCOs are the material type most widely used. However, these materials have some drawback, such as brittleness and a maximum transmittance for a certain sheet resistance. Alternative materials, such as metal foils, nanowires and organic conductors are discussed and ranked for their suitability in solar cells. At this moment, organic conductors have a performance inferior to inorganic conductors. Recent results of both modeling and experiments obtained at TNO demonstrate that the combination of TCOs and metal grids are the most viable option for improvement of TCO performance beyond the limits of a single material. For this demonstration commercial ITO on PET was used, on which metal grid was applied by easily upscalable wet chemical deposition techniques. The sheet resistivity was increased by a factor of over 400, with less than 5% loss additional in transmittance. A sheet resistance of 0.1 W/sq was obtained with a transparency above 83%.