Schwäbisch Hall, Germany
Schwäbisch Hall, Germany

Time filter

Source Type

Ott T.,Ulm University of Applied Sciences | Schonberger F.,Ulm University of Applied Sciences | Walter T.,Ulm University of Applied Sciences | Hariskos D.,Center for Solar Energy and Hydrogen Research | And 3 more authors.
Thin Solid Films | Year: 2015

Previous studies of Cu(In,Ga)Se2thin film solar cells showed that the long-term stability critically depends on the bias across the junction. As a result of a dark anneal the current-voltage (IV)-characteristics in the dark showed a blocking behavior with increasing anneal time. In the final stage the device exhibits an open circuit voltage (Voc) which is independent from the illumination intensity, a crossover of the dark and illuminated IV-characteristics and Vocsaturation for decreasing temperatures. These characteristics also occur in the initial state prior to the endurance test, however, at low temperature (< 200 K) measurements. We suggested a phototransistor model to explain the observed characteristics. The prerequisite of this model is the existence of a Schottky barrier at the back contact. In this contribution more insights into this phototransistor model and its experimental verification will be given and discussed. Finally we suggest how to avoid the effects of the back barrier with the help of a CuGaSe2layer at the back of the absorber and a Ga gradient through the absorber. These measures will be verified with simulations and compared to measurements on co-evaporated devices. © 2014 Elsevier B.V.

Reinhard M.,Karlsruhe Institute of Technology | Sonntag P.,Karlsruhe Institute of Technology | Eckstein R.,Karlsruhe Institute of Technology | Burkert L.,Manz CIGS Technology GmbH | And 4 more authors.
Applied Physics Letters | Year: 2013

Combining wide and narrow band gap absorbers in tandem solar cells is a promising approach to improve the energy conversion of sun light. In this work, we present hybrid tandem devices comprising monolithically connected copper indium gallium diselenide (CIGS) bottom cells and polymer top cells. The thin polymer:fullerene bulk heterojunction absorber layers were transferred onto the rough CIGS surface by a soft-contact lamination technique. Sputtered or solution-deposited top cathodes complete the tandem devices with enhanced open circuit voltages. © 2013 AIP Publishing LLC.

Adams J.,Bavarian Center for Applied Energy Research | Vetter A.,Bavarian Center for Applied Energy Research | Hoga F.,Bavarian Center for Applied Energy Research | Fecher F.,Bavarian Center for Applied Energy Research | And 4 more authors.
Solar Energy Materials and Solar Cells | Year: 2014

CuInGaSe2 (CIGS) thin film solar modules, despite their high efficiency, may contain three different kinds of macroscopic defects referred to as bulk defects, interface defects and interconnect defects. This occurs due to film's sensitivity to inhomogeneities during the manufacturing process. The result is a decrease of electrical power output from a cell or module. In this paper, we present the influence of macroscopic defects on the electrical behavior of CIGS thin film solar cells. To accomplish this, we investigated the relation between the IR-signal emitted of a defect in a cell (measured using illuminated lock-in thermography ILIT) and the respective open circuit cell voltage (Voc,cell) under low light conditions (< 100 W/m©2014 Elsevier B.V. All rights reserved.

Misic B.,Jülich Research Center | Pieters B.E.,Jülich Research Center | Theisen J.P.,Manz CIGS Technology GmbH | Gerber A.,Jülich Research Center | Rau U.,Jülich Research Center
Physica Status Solidi (A) Applications and Materials Science | Year: 2015

The influence of the i-ZnO/CdS buffer layer on intentionally produced defects in Cu(In,Ga)Se2 (CIGS) mini-modules is investigated by electroluminescence (EL) imaging. Macroscopic shunts of the dimension of 100 μm in length and several μm in width were produced by mechanically removing locally one or several of the layers during the module production process. After creating the defects the modules were finished in the usual way. It is found that heavy shunts were produced whenever the doped ZnO:Al came into contact with the Mo back contact. The decline of photovoltaic performance is seen by a decrease of the EL intensity of the damaged cell. In contrast, considerable shunt mitigation was observed whenever the i-ZnO/CdS buffer combination was present. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ott T.,Ulm University of Applied Sciences | Schonberger F.,Ulm University of Applied Sciences | Walter T.,Ulm University of Applied Sciences | Hariskos D.,Center for Solar Energy and Hydrogen Research | And 2 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2013

CIGS is the most promising technology for thin-film solar cells with record efficiencies of 20.4 % on laboratory scale and 17.8 % aperture area efficiency on a 900 cm- module. Another important factor besides the cell efficiency is the reliability and long term stability of the manufactured modules, which can be assessed by accelerated ageing. In this contribution the accelerated ageing of CIGS mini modules has been investigated. Therefore, modules were dark annealed under dry heat conditions at different temperatures. During the endurance test a positive or negative bias was applied to the cells. In regular intervals the IV- and CV-characteristics were measured at room temperature. After an overall stress time of 3500 h the IV-characteristics were determined under different illumination conditions (intensity, spectral illumination). Our previous publications suggest a barrier at the back contact to explain the observed parameter drifts. This contribution is focused on the influence of different bias conditions during the endurance test on the generation of a back diode and on the change of the acceptor concentration. These parameter drifts have an impact on the open circuit voltage, fill factor and on the appearance of a cross over between dark and illuminated IV-characteristics. The interpretation of the observed parameter drifts was supported by SCAPS simulations based on the above mentioned back barrier model. As an outcome of the simulations signatures for the existence of a back barrier diode were established. IVmeasurements, temperature dependent Voc measurements and SunsVoc measurements are helpful means to detect such back diodes. © 2013 SPIE.

Agency: Cordis | Branch: FP7 | Program: CP | Phase: ENERGY.2009.2.1.1 | Award Amount: 5.02M | Year: 2010

The Cu(In,Ga)Se2 (CIGS) on glass technology is already heading towards industrial maturity, but to meet the production cost target of below 0.6 /Wp in mid-term and below 0.4 /Wp in long-term, development of highly efficient flexible modules is an attractive option. The ultimate advantage of thin-film technology is the possibility of monolithically connected flexible modules produced with high speed roll-to-roll manufacturing systems. Partners of this proposal have already demonstrated a record efficiency of 14.1% for cells on polyimide and >15% efficiency cells on metal foil using static deposition processes. However, transfer of static deposition process to in-line deposition on moving substrates brings additional challenges for control of layer composition and interfaces. Choice of appropriate substrate and deposition processes to overcome problems of thermal mismatch-related stress are important for high performance and monolithic cell interconnection. The main goal of the project is to develop innovative flexible substrates and deposition processes suitable for the in-line and/or roll-to-roll production of highly efficient solar modules using thinner (< 1 micron) CIGS absorbers and with potential for production costs below 0.6 /Wp in future. The objective will be achived by developing novel concepts in growth of high quality layers and interfaces for efficiency improvement, aiming a new world record efficiency of 16% on polyimide and low-cost metal (mild steel and Al-based) foils. Also, the implementation of in-line compatible buffer, improvements in interconnect technologies and application of multifunctional top layer will lead to an advancement towards roll-to-roll manufacturability of integrated solar modules. This project will help research institutions to maintain a Global lead in CIGS field and will enable the European industries to implement the research excellence in industrial production of low cost flexible CIGS solar modules in future.

Agency: Cordis | Branch: H2020 | Program: RIA | Phase: LCE-02-2014 | Award Amount: 6.15M | Year: 2015

Prime objective of the Sharc25 project is to develop super-high efficiency Cu(In,Ga)Se2 (CIGS) solar cells for next generation of cost-beneficial solar module technology with the world leading expertise establishing the new benchmarks of global excellence. The project partners ZSW and EMPA hold the current CIGS solar cell efficiency world records of 21.7% on glass and 20.4% on polymer film, achieved by using high (~650C) and low (~450C) temperature CIGS deposition, respectively. Both have developed new processing concepts which open new prospects for further breakthroughs leading to paradigm shift for increased performance of solar cells approaching to the practically achievable theoretical limits. In this way the costs for industrial solar module production < 0.35/Wp and installed systems < 0.60/Wp can be achieved, along with a reduced Capex < 0.75/Wp for factories of >100 MW production capacity, with further scopes for cost reductions through production ramp-up. In this project the performance of single junction CIGS solar cells will be pushed from ~21% towards 25% by a consortium with multidisciplinary expertise. The key limiting factors in state-of-the-art CIGS solar cells are the non-radiative recombination and light absorption losses. Novel concepts will overcome major recombination losses: combinations of increased carrier life time in CIGS with emitter point contacts, engineered grain boundaries for active carrier collection, shift of absorber energy bandgap, and bandgap grading for increased tolerance of potential fluctuations. Innovative approaches will be applied for light management to increase the optical path length in the CIGS absorber and combine novel emitter, front contact, and anti-reflection concepts for higher photon injection into the absorber. Concepts of enhanced cell efficiency will be applied for achieving sub-module efficiencies of >20% and industrial implementation strategies will be proposed for the benefit of European industries.

A bath deposition solution for the chemical bath deposition of a metal sulfide layer, a process for the production of such a bath deposition solution, and a process for producing a metal sulfide layer on a substrate using such a bath deposition solution are provided. The bath deposition solution contains a metal salt, an organosulfide, a chelating agent which with metal ions of the metal salt forms a chelate complex and ammonium hydroxide.

Agency: Cordis | Branch: FP7 | Program: CP-IP | Phase: ENERGY.2011.2.1-2;NMP.2011.1.2-1 | Award Amount: 9.64M | Year: 2012

CIGS solar module technology on rigid glass substrate is already mature and industrial companies are producing hundreds of MWp each year. Bringing flexible CIGS solar modules to industrial maturity will yield the next breakthrough for further cost reduction by taking into account the inherent advantages of thin film technology, e.g. high throughput and large scale coating with less energy and material consumption. The aim of R2R-CIGS is to develop efficient flexible solar modules by implementing innovative cost-effective processes such that production costs below 0.5 /Wp can be achieved in large volume factories with annual capacity of 500MWp in future. The main objectives of this project are: Flexible solar cells on polymer film with 20% efficiency and mini-module with 16% efficiency by control of composition gradient, surface, and interface properties on nano-scale Transfer of innovative buffer layer process for roll-to-roll manufacturing and replacing problematic CBD-CdS by higher yield processes such as (spatial) ALD and ultrasonic spray Developing fully laser based patterning technology for monolithic interconnection in R2R pilot-line Scale-up of static multi-stage CIGS deposition process from laboratory scale towards inline R2R compatible processes Implementation of the up-scaled multi-stage CIGS deposition process into pilot lines for R2R manufacturing of flexible CIGS modules Development of moisture barrier with WVTR < 5x10-4 g/m2/d and cost-effective encapsulation Decrease cost of ownership for enabling production costs below 0.5 /Wp for a commercial plant with annual production of 500 MWp in future

Agency: Cordis | Branch: FP7 | Program: CP-FP | Phase: NMP-2008-2.4-2 | Award Amount: 5.41M | Year: 2010

Current production methods for thin film photovoltaics typically rely on costly, difficult to control (over large surfaces) vacuum-based deposition processes that are known for low material utilisation of 30-50%. NOVA-CI(G)S proposes alternative, non-vacuum ink-based simple and safe deposition processes for thin film CI(G)S photovoltaic cells. The low capital intensive, high throughput, high material yield processes will deliver large area uniformity and optimum composition of cells. The project objectives are to achieve competitive about 14% small area cell efficiency and to demonstrate the processes at high speed on rigid and flexible substrates while maintaining acceptably high efficiencies. The processes reduce cost of the CI(G)S layer by 75-80% in comparison to the evaporated CI(G)S, which translates into a 20-25% reduction of total module cost. Major scientific breakthroughs of the project include improved materials control in novel precursor materials by using nano-sized particles of specific chemical and structural characteristics and innovative ink formulation, to enable coating by simple processes while avoiding the use of toxic gases in subsequent process steps. This industry-led project constitutes the first essential step for a fully non-vacuum, roll-to-roll process aimed to achieve the solar module production cost below 0,8 /Wp that will make photovoltaic directly competitive to traditional energy generation.

Loading Manz CIGS Technology GmbH collaborators
Loading Manz CIGS Technology GmbH collaborators