We report on the use and effect of the alkali elements rubidium and caesium in the place of sodium and potassium in the alkali post deposition treatment (PDT) as applied to Cu(In,Ga)Se2 (CIGS) solar cell absorbers. In order to study the effects of the different alkali elements, we have produced a large number of CIGS solar cells with high efficiencies resulting in a good experimental resolution to detect even small differences in performance. We examine the electrical device parameters of these fully functional devices and observe a positive trend in the I –V parameters when moving from devices without PDT to KF-, RbF-, and eventually to CsF-PDT. A diode analysis reveals an improved diode quality for cells treat-ed with heavier alkalis. Furthermore, secondary ion mass spectrometry (SIMS) measurements reveal a competitive mechanism induced within the class of alkali elements in the CIGS absorber induced by the alkali post deposition treatment. (© 2016 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim)

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Effects of heavy alkali elements in Cu(In,Ga)Se2 solar cells with efficiencies up to 22.6%

We report on a new thin-film Cu(In,Ga)Se2 (CIGS) solar cell record efficiency of 217% In order to better understand this newest development, we describe the specific solar cell data as obtained from I–V measurement and diode analysis, quantum efficiency and secondary neutral mass spectrometry measurements We hope that such a description will help to exploit the potential of this promising thin-film solar technology even further (© 2015 WILEY-VCH Verlag GmbH &Co KGaA, Weinheim)

Properties of Cu(In,Ga)Se2 solar cells with new record efficiencies up to 21.7%

Thin film solar cells are favorable because of their minimum material usage and rising efficiencies. The three major thin film solar cell technologies include amorphous silicon (α-Si), copper indium gallium selenide (CIGS), and cadmium telluride (CdTe). In this paper, the evolution of each technology is discussed in both laboratory and commercial settings, and market share and reliability are equally explored. The module efficiencies of CIGS and CdTe technologies almost rival that of crystalline solar cells, which currently possess greater than 55% of the market share. α-Si is plagued with low efficiency and light-induced degradation, so it is almost extinct in terrestrial applications. CIGS and CdTe hold the greatest promise for the future of thin film. Longevity, reliability, consumer confidence and greater investments must be established before thin film solar cells are explored on building integrated photovoltaic systems.

A review of thin film solar cell technologies and challenges

We report on the interaction between intentional potassium doping of thin film Cu(In,Ga)Se2 (CIGS) solar cells, CIGS absorber composition, and device efficiency. Up to now high efficiency CIGS solar cells could not be produced with a gallium/(gallium + indium) ratio higher than 35%. The new doping process step does not only increase solar cell conversion efficiencies up to 20.8%, but also allows a shift in the CIGS absorber composition towards higher gallium content whilst maintaining this high efficiencies level. We find that the saturation of the open circuit voltages for higher gallium content that is normally observed can partially be overcome by the new doping procedure. This observation leads us to the conclusion that even on this high performance level CIGS solar cells still hold a potential for further development beyond the record values reported here. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Compositional investigation of potassium doped Cu(In,Ga)Se2 solar cells with efficiencies up to 20.8%

An organic light emitting diode display includes a substrate. A control electrode is on the substrate. A gate insulating film covers the control electrode. An input electrode and an output electrode are on the gate insulating film and face each other. An oxide semiconductor is between the input electrode and the output electrode and on the control electrode. A pixel electrode is on portions of the edges of the output electrode and is electrically connected. An organic light emitting member is on the pixel electrode. A common electrode is on the organic light emitting member. The oxide semiconductor and the pixel electrode may be of the same layer.

Organic Light Emitting Diode Display and Manufacturing Method Thereof

High-efficiency Cu(In,Ga)Se2 cells and modules

Thin-film solar cells based on Cu(In,Ga)(Se,S) 2 (CIGS) have demonstrated both high efficiencies and a high cost-reduction potential in industrial production. This way, future CIGS module production lines can be profitable even for scales below the GW range. Among the different technologies, only the coevaporation method has demonstrated efficiencies above 20%, approaching the record values of polycrystalline Si cells. The main focus of this contribution is on the new results of the ZSW cell line with efficiencies above 20%, as well as on the mini-module line on glass substrates. Mini modules (10 cm × 10 cm) with efficiencies in the range of 17% give a proof of concept for industrial-sized modules. ZSW is also developing flexible cells and modules, transferring the processes from the glass-based technology. We achieved 18.6% cell efficiency on metal substrates and a 15.4% efficient mini module could be demonstrated with adapted methods of module patterning. In order to develop industrially relevant processes for foils, we are running a roll-to-roll deposition plant. Additionally, we have improved CIGS cell efficiencies with alternative buffers to certified 19.0% for solution-grown Zn(O,S), to 16.4% for sputtered Zn(O,S), and 17.1% for evaporated In 2S 3. Our cells deposited by vacuum-free methods exhibit an efficiency of 8.5% with a nanoparticle-based process.

CIGS Cells and Modules With High Efficiency on Glass and Flexible Substrates

An organic light-emitting component, having a substrate, a first electrode arranged on the substrate, a layer stack that is arranged on the first electrode and that has at least one organic layer and a second electrode arranged on the layer stack. The layer stack is suitable for emitting electromagnetic radiation during operation. The component also has a receiver device, which is suitable for drawing energy from an alternating electromagnetic field and for converting this energy at least partially into electrical energy and for making this energy available to the layer stack.

Organic light-emitting component

Zn(O,S) is a promising candidate to replace the commonly used CdS buffer layer for Cu(In,Ga)Se2 (CIGS) thin-film solar cells due to its non-toxicity and its potential to enhance the conversion efficiency of the CIGS solar cell. The composition of chemical bath deposited (CBD) and sputtered Zn(O,S) layers with thicknesses well below 100 nm was determined by sputtered neutral and secondary ion mass spectrometry (SNMS and SIMS). Despite numerous mass interferences of double-charged atoms and dimers with single Zn, O and S isotopes, we developed an evaluation algorithm for quantification of SNMS depth profiles of Zn(O,S) layers. In particular, the superposition of double-charged S and Zn atoms with O and S isotopes is accounted for numerically in the quantification procedure. For sputtered Zn(O,S) layers, the S/(S + O) atomic ratio and the vertical composition profile can be controlled by the O2 content in the gas flow and the substrate temperature during sputtering whereas for CBD Zn(O,S) the S/(S + O) ratio is constant around 0.7–0.8. A Cu-depleted layer of about 5 nm on the CIGS surface after buffer deposition was observed for both preparation methods. With negative SIMS, we found more hydroxides and carbon residues in CBD Zn(O,S) as compared to sputtered layers. Best cell performance with sputtered Zn(O,S) layers was achieved for S/(S + O) ratios of 0.25–0.40, yielding efficiencies up to 13%. Our solar cells with CBD Zn(O,S) buffers exhibit higher efficiencies due to an improved open-circuit voltage. Copyright © 2013 John Wiley & Sons, Ltd.

Depth profiling with SNMS and SIMS of Zn(O,S) buffer layers for Cu(In,Ga)Se2 thin-film solar cells

An encapsulation for an organic electronic component, characterized in that the component, encapsulated in a dimensionally stable capsule, is at least partially covered with a protective film

Carsten Tschamber

Papers

High-efficiency Cu(In,Ga)Se2 cells and modules

CIGS Cells and Modules With High Efficiency on Glass and Flexible Substrates

Organic light-emitting component

Depth profiling with SNMS and SIMS of Zn(O,S) buffer layers for Cu(In,Ga)Se2 thin-film solar cells

Encapsulation for an organic electronic component, its production process and its use