Leybold Optics supplies vacuum systems for CIGS applications

CIS or CIGS thin film modules consist of I-III-VI compound semiconductors that are used in various combinations. The abbreviation CIGS stands for the elements that are used: copper (Cu), indium (In), gallium (Ga) and/or selenium (Se). There is a great potential for savings in CIGS technology - not only as far as energy expenditure is concerned, but also in respect of material and manufacturing costs. Thanks to the thinner layer thicknesses and depending on the substrate, flexible solar modules can also be manufactured.

Leybold Optics offers the full range of equipment for all vacuum based CIGS processes, be it on glass substrates or flexible substrates. In the first step, the substrate, for instance glass, is initially coated with molybdenum (Mo) that serves as back contact. Then the absorber is produced from the elements copper, indium and gallium, with subsequent heating in a selenium atmosphere.

 The final, conductive and transparent front contact consists of aluminum-doped zinc oxide (AZO). Buffer layers that are for instance made of indium sulfide and cadmium sulfide (In2S3 and CdS) and non-doped zinc oxide (ZnO) are located between absorber and front contact.

 The molybdenum and zinc oxide layers are produced by means of sputtering. For these applications, Leybold Optics offers horizontal (H-series) as well as vertical (A-series) sputtering systems. The absorber on the contrary may be produced by means of thermal evaporation or by sputter coating followed by subsequent heating in a selenium atmosphere.

Leybold Optics has developed the selenium evaporator Selenia especially for this selenium process - but it may also for other applications. The system, already successfully marketed, uses linear selenium sources, to ensure excellent layer homogeneity, even at extremely large throughputs. The design of Selenia allows the selenium reservoir to be replenished while simultaneously running production. The system can be used for all complex evaporation processes on flat substrates for photovoltaic applications. In view of the small amounts of selenium used, the high degree of productivity, the simple operation and low maintenance requirements, Selenia is a unique solution that has an extremely positive effect on the cost of ownership.

The RaPiT (Rapid Thermal Process Oven) rounds off the range of products offered by Leybold Optics to produce the all important absorber layer. The semiconductor is formed inside the RaPiT with the aid of a reactive gas. In cooperation with a customer, the RTP furnace was developed by Leybold Optics with the objective of meeting the high requirements on a stringent process control and precise temperature guidance, while simultaneously achieving highest levels of productivity.

Further process steps to apply the buffer and the subsequent front contact layer are required to complete the CIGS solar cell. In this respect too, the machine platforms of the Leybold Optics H- and A-series with their corresponding configuration for the production of the zinc oxide (ZnO) and intrinsic zinc oxide (i-ZnO) layers significantly contribute to the manufacture of solar cells in production lines.

For complex, flexible applications, Leybold Optics offers the Roll-to-Roll coating system, also called a web-coater. The process is designed for substrates such as metal films or flexible synthetic materials and permits coating methods such as sputtering, evaporation, CVD (chemical vapor deposition) or combined solutions.

The substrates are transported via a conveyor from roll to roll and are vacuum coated in the process, without any contact on the coated surface. With its special 360° design, this patented Leybold technology offers a fully automatic process sequence, which apart from the production of flexible solar cells, may be used for a wide variety of other applications.

In the meantime, CIGS systems from Leybold Optics are being used in large production facilities by world market leaders. All our products are characterized by their high degree of reliability, availability and flexibility. Depending on the desired processes, the system concepts can be of vertical or horizontal design.

 Source:

(1) Matthias Fawer, Bank Sarasin Sustainable Investment, Basel, 11th Solar study

Image caption:

Leybold Optics versatile sputter tool for PV applications

Image source:

Leybold Optics, Alzenau/Germany

Company Profile:

Leybold Optics GmbH is one of the world's leading suppliers of vacuum technology. It also develops processes and manufactures complex high-end coatings. This reputed thin film specialist sets milestones in the fields of sputtering, PEVCD, plasma assisted evaporation, automation and software.

It is organized into two divisions: Optics and Glass & Solar. The Glass & Solar division portfolio comprises vacuum systems for the photovoltaic industry and machines that are used to coat architectural glass, displays and other large-area applications. The Optics division markets deposition systems for precision optics, ophthalmic lens coating, the automotive and the electronics industry.

The foundation stone of its success was laid over 160 years ago by the founders and inventors

Ernst Leybold and Wilhelm Carl Heraeus. Their pioneering spirit and dedication to research and the development of new production procedures is reflected in the market standards that have gained worldwide recognition since the company was founded. Today, Leybold Optics, which is traditionally committed to innovation and quality, is a global company that has more than 500 employees across the world.

Leybold Optics GmbH

Jörg Hahn

Manager Sales and Marketing Glass & Solar

Siemensstraße 63755 Alzenau Germany

Phone +49 (0)6023 500-0 oder-188

Fax +49 (0)6023 500-9188

joerg.hahn@leyboldoptics.com

www.leyboldoptics.com

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