Organic Electronics (OLEDs & OPVs)

Over the last two decades, rapid advances in research and development in organic electronics have resulted in many exciting discoveries and applications, including Organic Light-Emitting Diodes (OLEDs) for information display and illumination, Organic Photovoltaic solar cells (OPVs), photodetectors, chemosensors, and logic devices. These devices operate in a similar way to traditional electronic devices (based on inorganic semiconductors) but use organic (carbon-based) materials. This provides potential for simpler processing, tunability (through chemical design) and lower cost of production. Thin films of organic materials tend to be much less rigid than inorganic materials, leading to potential to produce novel flexible and conformable devices such as rollable TV panels and bendable mobile phone screens. Commercialisation of the technology has been achieved through the introduction of OLED TV and mobile phone panels to the market with brighter, crisper displays, but research is ongoing to produce improved materials and device structures.

Kurt J Lesker has been manufacturing PVD tools for organic electronics research for over 20 years, having supplied many tools to leading research institutions globally. Because of this, our team of dedicated applications, design and vacuum experts have developed unrivalled know-how about the production of systems to meet the stringent demands of this innovative research community.

Vacuum processing of organic devices such as OLEDs and OPVs is, at first glance, straightforward as most material films are produced by simple thermal evaporation techniques. However, system requirements become more complicated when considering some of the unique challenges organic materials and devices bring.

The evaporation temperature of most organic materials is low, typically (and often significantly) less than 500°C - temperatures at which regular thermal boat sources are simply not effective. Special sources optimised for operation in this reduced temperature range are required. Film structure and quality is highly dependent on factors such as the deposition rate, thickness and substrate temperature, meaning highly accurate control of both the evaporation process and of additional components such as substrate heaters, is highly critical. Co-deposition is common, e.g. host: dopant layers in or donor:acceptor blends in OPVs, so systems must have the ability to control multiple sources simultaneously, with the same high level of accuracy but with no crosstalk or cross-contamination. Kurt J Lesker can attain ratios as high as 1000:1.

Practical considerations are also vital. Much of the R&D work on organic electronics is materials-driven, meaning large libraries of materials are often in use. Systems must be designed for maximum flexibility - having many sources available and/or the ability to rapidly access and change materials. Materials often need to be screened quickly for effectiveness, allowing little time for optimisation. Combinatorial tools; those allowing multiple device structures to be produced in a single process, provide a significant advantage in this process. The complex structures required for OLED and OPV device work often require various shadow masks to be used at different stages of production, so in-situ mask transfer is important. Many organic materials, and particularly the device structures produced, are prone to degradation in the presence of oxygen and moisture, so atmosphere-controlled gloveboxes are essential.

We understand that tool personalization that addresses a researcher's unique requirements is critically important and we have therefore developed and support an extensive capabilities portfolio including:

• Low Temperature Evaporation LTE sources with unique plug-in base for easy swap-out designed for effective deposition of volatile organic materials in the range of 50-600°C
• Rapid source cooling using water-cooled HydraVap™ evaporation sources
• Resistive thermal heating sources for evaporation of high melting point materials (e.g. metals)
• Industry-leading evaporation rate reading and PID control for highly accurate, stable, organic film deposition
• Co-deposition as standard to produce complex and precise blended layers
• Combinatorial capability using single or dual-blade wedge tools
• Shadow mask capability with in-situ mechanical transfer for production of complex device structures
• Heating and cooling substrate platens up to 200mm x 200mm
• RF bias for cleaning of substrates prior to deposition
• Space-optimised process chamber geometries to allow maximal source count possibilities for high throughput materials research or complex multi-layer stack structures
• In-situ film measurement to accurately monitor real-time deposition parameters
• Process chamber shielding to ensure minimal crosstalk between each deposition source and quartz crystal monitors
• Load lock chambers to reduce takt time and increase productivity
• Cluster tool options with multi-chambers for high throughput and complex device structures with either in-vacuum transfer or transfer through a glovebox
• Glovebox compatibility as standard for handling of sensitive materials and devices
• Glovebox options including robot encapsulation, spin-coater, hot-plate, UV cure and solar simulator
• Fully integrated film recipe and system control using our Lesker eKLipse™ process control platform for precise, repeatable deposition conditions

We want to hear from you. Our thin film experts and service support team are eager to help enable your important research.