To maintain typical textile properties, smart designs of light emitting devices are printed directly onto textile substrates. A first approach shows improved designs for alternating current powder electroluminescence (ACPEL) devices. A configuration with the following build-up, starting from the textile substrate, was applied using the screen printing technique: silver (10 µm)/barium titanate (10 µm)/zinc-oxide (10 µm) and poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (10 µm). Textile properties such as flexibility, drapability and air permeability are preserved by implementing a pixel-like design of the printed layers. Another route is the application of organic light emitting devices (OLEDs) fabricated out of following layers, also starting from the textile substrate: polyurethane or acrylate (10–20 µm) as smoothing layer/silver (200 nm)/poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (35 nm)/super yellow (80 nm)/calcium/aluminum (12/17 nm). Their very thin nm-range layer thickness, preserving the flexibility and drapability of the substrate, and their low working voltage, makes these devices the possible future in light-emitting wearables.

The identification, fine‐tuning, and process optimization of appropriate hole transporting layers (HTLs) for organic solar cells is indispensable for the production of efficient and sustainable functional devices. In this study, the optimization of a solution‐processed molybdenum oxide (MoOx) layer fabricated from a combustion precursor is carried out via the introduction of zirconium and tin additives. The evaluation of the output characteristics of both organic photovoltaic (OPV) and organic light emitting diode (OLED) devices demonstrates the beneficial influence upon the addition of the Zr and Sn ions compared to the generic MoOx precursor. A dopant effect in which the heteroatoms and the molybdenum oxide form a chemical identity with fundamentally different structural properties could not be observed, as the additives do not affect the molybdenum oxide composition or electronic band structure. An improved surface roughness due to a reduced crystallinity was found to be a key parameter leading to the superior performance of the devices employing modified HTLs.

The enhancement of the out‐coupling efficiency of organic light‐emitting diodes (OLEDs) is still the subject of research and development. Bottom‐emission OLEDs emit light through the glass substrate into air. Due to the difference of the refractive indices between glass and air, a significant amount of light is reflected at the glass–air interface back into the glass because of total internal reflection. One possibility to avoid total internal reflection at the glass–air interface is the use of lenses. Herein, the concept of macrolenses for pixelated OLEDs is presented. For the design of the lenses, the vertical and horizontal dimensions of the OLED have to be considered, and the contact angle of the lens has to be adapted to the geometrical conditions. A process based on inkjet etching and inkjet printing has been developed which now allows the printing of lenses with defined radius and contact angle. Measurements of the luminance show an improved out‐coupling efficiency.

Modern lighting is expected to be light weight, flexible, efficient, non-expensive and environmentally friendly fabricated. Organic light emitting diodes (OLEDs) meet all these requirements and can be manufactured using inexpensive and roll-to-roll compatible printing techniques. They, however, often use low work function, highly reactive metals, such as barium and calcium to facilitate electron injection, deposited using expensive and non-continuous vacuum techniques. Efficient and stable alternatives can be found in the aliphatic amines, polyethylenimine (PEI) and polyethylenimine(ethoxylated) (PEIE), that shift the work function of aluminum favorably for electron injection. This work demonstrates ultrasonic spray coating of PEI(E) as electron injection and transport layer for OLEDs, reducing the work function of the aluminum cathode by 0.355 eV allowing a luminous efficacy comparable to that of the OLEDs using calcium/aluminum electrodes. Slightly higher luminous results are noted for the OLEDs with spin coated PEI(E), indicating that the surface morphology and thickness of the PEI(E) layer are crucial factors: ultrasonic spray coated PEI(E) layers have an increased overall thickness and surface roughness. This study shows the potential of ultrasonic spray coating and the suitability of PEI(E) as excellent electron injection and transport layer for OLEDs and paves the way towards fully spray coated OLEDs.