Kang, H., Hwang, Y., Kang, Cm. et al.

Sci Rep 13, 14070 (2023).

https://doi.org/10.1038/s41598-023-41033-4

This research explores electrical crosstalk in high-resolution OLED microdisplays impacting color distortion, especially in AR/VR applications. Through simulations and experimental measures, it was found that decreasing sheet resistance in the common organic layer elevated crosstalk, and increasing pixel density led to a color gamut reduction.

How Laoss Simulation was used

Simulation process. Commercial software LAOSS (Fluxim) which used 2 + 1D finite element model based on the conductivity of the common layer17,18 and J–V–L characteristics of the fabricated white OLED were used for the electrical crosstalk calculation.

M. Battaglia, E. Comi, T. Stadelmann, R. Hiestand, B. Ruhstaller, E. Knapp;

APL Mach. Learn. 1 September 2023; 1 (3): 036108.

https://doi.org/10.1063/5.0139707

A data-driven approach using deep learning predicts parameters of a solar cell model based on electroluminescence (EL) images. Using 75,000 synthetic EL images, the study employs a deep ensemble of 17 modified VGG19 neural networks to add uncertainty estimates. This approach, tested on four solar cell samples, bridges deep learning with engineering applications needing real-time physical model parameterizations with confidence intervals. The network's predictions showed an average deviation of 0.2% (max 10%) in junction voltage values, confirming the method's validity.

How Laoss was Used

Laoss, a simulation model, was used to model the measured solar cell samples and generate simulated electroluminescence (EL) images. These images were then used to train the inverse convolutional neural network (CNN) model. The Laoss parameterization used to generate the training data is discussed in the paper. The inverse model was trained on a set of simulated EL images, and the network architecture and training of the inverse CNN model are explained in detail. The results of the inverse model method are evaluated, and the changes in the CNN structure and training hyperparameters required to implement and train such a deep ensemble CNN inverse model are discussed.

Kamijo, T., van Breemen, A.J.J.M., Ma, X. et al. A touchless user interface based on a near-infrared-sensitive transparent optical imager. Nat Electron (2023).

https://doi.org/10.1038/s41928-023-00970-8

Researchers have developed a touchless user interface based on a visually transparent near-infrared-sensitive organic photodetector (OPD) array. The touchless interface can be used on top of a display, eliminating the need for physical contact.

The OPD array is designed with optical transparency in mind, using printed copper grids and patterned organic photodetector subpixels. The design optimization results in a high photodetectivity of 10^12 Jones at 850 nm and a visible-light transmittance of 70%.

The touchless user interface can be used with a penlight or through gesture recognition, providing a hygienic and convenient alternative to traditional touch screens. The technology has potential applications in automated teller machines (ATMs), ticket vending machines, and kiosks, where hygiene is a concern. It is a scalable and flexible solution that can be integrated into a variety of display applications without size limitations or calibration requirements. 2D FEM simulations for the surface potential and the current density distributions derived from the printed Cu grid structure .

How Fluxim’s Research Tools were used

Setfos

Numerical electro-optical simulations for the photogenerated J–V curves of our NIR-sensitive OPDs were performed by using Setfos.

The VLT of the parallel OPD subpixel array was calculated by the summation of the simulated optical transmittance for each component using Setfos

Laoss

2D FEM simulations for the surface potential and the current density distributions derived from the printed Cu grid structure for our NIR-sensitive OPDs were performed by Laoss 4.0

Soobin Sim, Jinha Ryu, Dae Hyun Ahn, Hyunsu Cho, Chan-mo Kang, Jin-Wook Shin, Chul Woong Joo, Gi Heon Kim, Chun-Won Byun, Nam Sung Cho, Hyoc Min Youn, Young Jae An, Jin Sun Kim, Hanyung Jung, and Hyunkoo Lee,

Opt. Express 30, 24155-24165 (2022)

doi.org/10.1364/OE.463095

Herein, the color gamut change by optical crosstalk between sub-pixels in high-resolution full-color organic light-emitting diode (OLED) microdisplays was numerically investigated. The color gamut of the OLED microdisplay decreased dramatically as the pixel density of the panel increased from 100 pixels per inch (PPI) to 3000 PPI.

Both Setfos and Laoss were used by the research team to perform optical simulations. To conduct the optical crosstalk simulation, the EL spectra was simulated using Setfos and the simulated EL spectra were well matched with the measured EL spectra. The transmittances of the R and G CFs provided by Laoss.

Gregory Burwell, Oskar J. Sandberg, Wei Li, Paul Meredith, Matt Carnie, and Ardalan Armin

Sol. RRL 2200315, 1 , (2022)

DOI: 10.1002/solr.202200315

Compared to their use as organic solar cells (OSCs) for standard outdoor solar harvesting, indoor OPV (IOPV) devices operate at low light intensities and thus demonstrate different area-scaling behavior. In particular, it appears as though the performance of large-area IOPV devices is much less affected by the sheet resistances of the transparent conductive electrodes (a major limit in OSCs), but instead by factors such as their shunt resistance at low light intensities. Herein, the key parameters for improving the efficiency of large area IOPV using drift-diffusion and finite element modeling (FEM) are examined. The scaling behavior at low-light intensities is theoretically and experimentally probed and demonstrated using the model PM6:Y6 system.

Takeshi Kamijo, Suzanne de Winter, Pradeep Panditha, and Eric Meulenkamp

ACS Applied Electronic Materials 2022 4 (2), 698-706

DOI: 10.1021/acsaelm.1c01116

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.

The spatial luminance distribution was simulated by LAOSS - large area organic semiconductor simulation software.

Diogo Castro, Vera C. M. Duarte, and Luísa Andrade

ACS Omega Article ASAP

DOI: 10.1021/acsomega.2c03560

The increasing demand for solar energy has led researchers worldwide to develop new photovoltaic technologies.

Among these, perovskite materials are one of the most promising candidates, with a performance evolution unparalleled in the photovoltaic field.

However, this thin-film technology is not yet available at a commercial level, mainly due to upscaling issues. This work studied the best design options for upscaling single cells into modules by minimizing electrical losses in the device substrates.

Fluxim`s Laoss software for upscaling was used to test and optimize different substrate sizes and designs and to predict several performance outcomes from experimentally fabricated single cells.

The results showed that it is possible to retain most of the energy production when upscaling from a single cell to a module if the appropriate design for an efficient monolithic device is used.

Lieven Penninck, Matthias Diethelm, Stéphane Altazin, Roman Hiestand, Christoph Kirsch, Beat Ruhstaller

Journal of the SID 26, 546 (2018)

https://doi.org/10.1002/jsid.671

Matthias Diethelm, Lieven Penninck, Stéphane Altazin, Roman Hiestand, Christoph Kirsch & Beat Ruhstaller

Journal of Information Display, 2018, 19, 61

https://doi.org/10.1080/15980316.2018.1428232

Abstract:The resolution of organic light-emitting diode (OLED) displays is increasing steadily as these displays are adopted for mobile and virtual reality (VR) devices. This leads to a stronger pixel crosstalk effect, where the neighbors of active pixels unintentionally emit light due to a lateral electric current between the pixels. Recently, the crosstalk was quantified by measuring the current flowing through the common hole transport layer between the neighboring pixels and comparing it to the current through the active pixel diode [S.-K. Kwon, K.-S. Kim, H.-C. Choi and J. H. Kwon, presented at the International Meeting on Information Display, Jeju, South Korea, 2016]. The measurements showed that the crosstalk is more crucial for low light levels. In such cases, the intended and parasitic currents are similar. The simulations performed in this study validated these measurement results. By simulations, we quantify the crosstalk current through the diode. The luminous intensity can be calculated with the measured current efficiency of the diodes. For low light levels, the unintended luminance can reach up to 40% of the intended luminance. The luminance due to pixel crosstalk is perceivable by humans. This effect should be considered for OLED displays with resolutions higher than 300 PPI.

C Kirsch, S Altazin, R Hiestand, T Beierlein, R Ferrini, T Offermans, L Penninck, B Ruhstaller

Int. Jnl. of Multiphysics Volume 11 · Number 2 · 2017