Abstract
The transparent conductive electrode (TCE) is a key component of organic light-emitting diodes (OLEDs). High-resolution printed metal grids are a promising alternative to indium tin oxide (ITO). We present results for evaporated OLEDs with a printed copper (Cu) grid with line width below 3 μm. The use of a thick doped hole injection layer (HIL) prevented electrical shorts and resulted in good quality OLEDs with acceptable leakage current. We report a detailed analysis of the microscopic uniformity of light emission and compare the measured data with simulations based on finite element modeling (FEM) to investigate various factors that contribute to differences between the Cu grid OLED and ITO reference device. This insight resulted in design rules that enable a luminance of the Cu grid OLED that can potentially equal that of an ITO-based equivalent OLED by using a very fine pitch and narrow line width of 5 μm and 250 nm, respectively, within the capabilities of state-of-the-art printing technology.
Highlights
Organic light-emitting diodes (OLEDs) are widely applied in the display industry.[1]
The line width, pitch, and line thickness of the printed Cu grid were varied between 1.0−3.5 μm, 15−30 μm, and approximately 50−210 nm, respectively
The transmittance of the printed Cu grid is flat in the visible light region and very close to indium tin oxide (ITO)’s transmittance
Summary
Organic light-emitting diodes (OLEDs) are widely applied in the display industry.[1]. ITO has several drawbacks, such as limited flexibility due to its inherent brittleness[3] and higher sheet resistance (approximately >20 Ω□) on flexible low-temperature plastic substrates due to lower possible annealing temperature. To overcome these drawbacks, various alternative TCEs have been investigated; one of the most promising candidates is a metal grid. The choice for copper as grid material would make TCEs cheaper than those based on gold or silver, still with the potential to outperform ITO
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
