In the blog, we explore charge carrier mobility in organic and perovskite semiconductors, detailing measurement techniques, focusing on IV characterization of single-carrier devices, and examining the Mott-Gurney law through device simulations.
Read the full research blog here: https://www.fluxim.com/charge-carrier-mobility-measurement-techniques
Read MoreDiscover the groundbreaking 33.9% efficiency record set by Longi for a perovskite/silicon tandem solar cells in. Learn how simulations can be used to optimize performance and explore the potential of multi-junction solar cells.
Read the full blog here: https://www.fluxim.com/perovskite-silicon-tandem-pv-record-updates
Read MoreWe prepared a tutorial to summarize the fundamental equations to simulate the electrical behaviour of OLEDs, photodetectors and solar cells. We take as an example the response speed of narrowband organic optical upconversion devices.
Check the full discussion here: https://www.fluxim.com/tutorial-on-drift-diffusion-simulations
Read MoreNon-metalized contact pads and shared electrodes can undermine the accuracy of solar cell and LED measurements due to high contact resistance, distorting current-voltage (IV) curves and resulting in incorrect maximum-power-point (MPP) and open-voltage circuit (Voc) values. However, solutions exist: metallizing contact pads with gold or silver can reduce resistance issues, and avoiding common electrodes in multi-pixel designs can further enhance measurement accuracy, leading to improved reliability and efficiency in solar cells and LEDs.
Read the Full white paper here: measurement-accuracy-of-led-and-pv-devices-with-a-common-electrode
Read MoreSetfos can analyze angular-dependent PL data collected by Phelos to get information about the properties of an organic emitter, such as the orientation of the dipoles and the width of the emission zone. With this analysis, we are able to optimize the characteristics of our OLEDs for high EQEs.
Check our description here: https://www.fluxim.com/dipole-orientation-led
Read MoreDive into the world of mobility in solar cells, and explore how CELIV measurements help determine charge carrier mobility in thin-film solar cells like perovskite and organic solar cells. Learn about various CELIV techniques and their applications in this comprehensive research blog.
Check the full tutorial here: https://www.fluxim.com/understanding-mobility-celiv-measurements
Read MoreThe monolithic module design is a suitable solution to upscale the lateral dimensions of perovskite solar cells. The device's active area is divided into smaller cells with an interconnection gap. The narrower the subcell, the lower the resistance of each subcell with consequent improvement of the FF. However, the interconnecting gap between each subcell is an inactive area, that reduces the total efficiency of the module. The interconnection is composed of lines P1, P2, and P3, which respectively separate the TCO, the photoactive layer, and the top contact between consecutive subcells.
We used the simulation software Laoss to optimize a perovskite photovoltaic minimodule. This procedure can replace the standard experimental trial-and-error approach that is commonly used to upscale perovskite solar cells.
Check the full tutorial here: https://www.fluxim.com/perovskite-solar-cell-upscaling-prevision
Read MoreThe presence of ions limits the charge extraction in perovskite solar cells, causing current losses. We used drift-diffusion simulation to validate this hypothesis and propose solutions to limit their influence – hence optimizing the power conversion efficiency (PCE).
Read the full post here: https://www.fluxim.com/mobile-ions-perovskite-solar-cells
Read MoreThe performance of light-emitting (LEDs) and photovoltaic (PV) devices depends on the quality of the photoactive semiconductor material. The unintentional introduction of defects in the semiconductor material due to material impurities or during the fabrication process causes the deviation from optimal performance.
These defects are referred to as trap states, or in short “traps”, which are energetic states within the bandgap of a semiconductor. In general, traps can occur due to material impurities (in the bulk) or at the interfaces between layers of different materials.
In the following blog post, we will present how to characterize the trap states with the technique called thermally stimulated current (TSC). We also propose a method to reliably interpret the TSC results based on drift-diffusion simulations.
Check the full tutorial here: https://www.fluxim.com/trap-states-perovskite-solar-cells
Read MoreOLEDs made by thermally-activated delayed fluorescence (TADF) materials as emitters promise an IQE of 100%. Here, we want to present an analysis of the influence of non-radiative recombination rates (knrs and knrt) on the device efficiency as well as how to determine them from experiments. As we will see, the knr rate influences PLQY, and consequently ELQY, hence the negative impact on EQE.
First, to determine the non-radiative decay rates, we need to extract the rates kf, krisc, and kisc by fitting transient photoluminescence (trPL) measurements of TADF films.
Check the full discussion here: https://www.fluxim.com/determining-non-radiative-decay-rates-in-tadf-compounds
Read MoreHow do we perform aging experiments that are tailored to emerging PVs? This blog post summarizes the crucial guidelines that have been proposed by the community working on Perovskite Solar Cells (PSCs) to properly assess the stability of PSCs. These guidelines have been added to the existing indications provided by the ISOS protocols developed for Organic Solar Cells.
Read the full post here: https://www.fluxim.com/isos-protocols-stability-perovskite-solar-cells
Read MoreIt is challenging to increase the device area of optoelectronic devices based on perovskite and organic materials without losing performance. One of the key issues is the high sheet resistance (Rs) of the transparent conductive oxide (TCO). Combining the TCO with a metallic grid reduces the ohmic losses, but what is the grid geometry that maximizes performance?
In this tutorial, we will show you, how to use the simulation software Laoss and its optimization feature to quickly find the grid geometrical features for maximum power output.
Check the full tutorial here: https://www.fluxim.com/mpp-large-area-organic-solar-cells
Read MoreWe introduced a theoretical treatment of photon emission and recycling in optoelectronic semiconductor devices that is free of non-physical divergencies. Here, we now show the application of this framework to the assessment of the impact of PR on the light extraction efficiency in perovskite LEDs. This treatment goes from the analysis of contributing photonic modes in single emitter slab configurations to the evaluation of the external LED quantum efficiency in realistic device stacks.
Check the full tutorial here: https://www.fluxim.com/metal-halide-perovkiste-light-emitting-diodes
Read MoreTransient photoluminescence (trPL) characterization experiments allow to analysis charge carrier dynamics and identify the recombination channels of the device structure under investigation.
Useful information that can be extracted includes the quantification of radiative and non-radiative lifetimes, charge carrier extraction from differential lifetime computation, and the influence of the interfaces on the recombination mechanism. Fitting the experimental results with simulations further supports the analysis of the obtained data. However, qualitatively comparable fittings can be obtained with different sets of simulation parameters.
Using the fully-coupled, 1-dimensional optoelectronic simulation software Setfos, the trPL signal of a simple glass/perovskite structure was simulated and a routine is suggested to ascertain the reliability of the results. This routine is based on experimentally measured material properties and the analysis of the band diagram evolution during the photoluminescence transient. The validity of the simulated trPL is also recursively verified by fitting the decay with a bi-exponential function to extract the lifetimes of the recombination mechanisms.
Check the full tutorial here: https://www.fluxim.com/transient-photoluminescence-perovskite-pvs
Read MoreWe describe a novel simulation approach for excitons in organic light-emitting diodes (OLEDs). We combined a 1D drift-diffusion model with a 3D master equation.
Our approach effectively combines the computational efficiency of a 1D drift-diffusion solver with the physical accuracy of a discrete 3D ME model, where excitonic long-range interactions for energy transfer can be taken into account.
We show that such a hybrid approach can efficiently describe the steady-state and transient behavior of typical OLEDs reported in the literature.
Check the full discussion here: https://www.fluxim.com/oled-with-master-equation-for-excitons
Read MoreThe open-circuit voltage (Voc) is the electrical potential difference between the two terminals of a solar cell, when there is no external load applied, hence no electric current flows. Correspondingly, this means that, when a voltage equivalent to the Voc is applied to the terminals of the solar cell, the recombination current (Jrec, which typically follows a non-ideal diode equation) and the photocurrent (Jph, the current generated by illuminating the solar cell) are equal, hence the net current is zero (Jrec=Jph at V= Voc).
Solar cells often present also non-radiative recombination mechanisms, in addition to the radiative one, as a result of poor material quality and non-idealities. To increase the Voc and thus potentially the power conversion efficiency, it is necessary to minimize the ΔVoc,nrad. It is, therefore, necessary to quantify the total loss and determine its origin.
Electroluminescence (EL) and photoluminescence quantum yield (PLQY) allow to directly extract the ΔVoc,nrad for thin-film solar cells such as perovskite solar cells, kesterite, perovskite, organic, or quantum dot. solar cells.
After quantifying the losses, the combination of capacitance-voltage (CV), temperature-dependent voltage characteristics (JV-T), and capacitance-frequency (Cf-T) measurements are essential to identify the recombination mechanisms.
Check the full tutorial here: https://www.fluxim.com/voc-losses-perovkiste-solar-cells
Read MoreA theoretical description of light emission, propagation, and re-absorption in semiconductor multilayer stacks is derived based on the transverse Green’s function of the electromagnetic field in the presence of a complex dielectric. The framework obtained is shown to reproduce the generalized Kirchhoff relations between the luminescent emission from metal halide perovskite slabs under uniform excitation and the slab absorptance of light with an arbitrary angle of incidence. Finally, consistent treatment of re-absorption provides the local rate of secondary photogeneration required for the consideration of photon recycling in an optoelectronic device simulator that includes the effects of charge transport.
Check the full tutorial here: https://www.fluxim.com/photon-recycling-in-perovskite-solar-cells
Read MoreWe present a combined experimental/simulation analysis of a set of 4 OLEDs with 2 systematically varied guest dopants in the EML. A numerical electro-optical model is employed, demonstrating one consistent parameter set that describes both steady-state and AC characteristics of all devices. The model accounts for charge transport, trapping, polar layers, and excitonic loss processes. These are inducing an efficiency roll-off that can be correlated with the shape of the emission zone and the guest dopant concentrations. Furthermore, starting from the resulting parameter set, we show routes for optimized TADF OLDEs with a reduced roll-off.
Check the full discussion here: https://www.fluxim.com/tadf-oled-optimization-excitons
Read MoreIn this tutorial, we are demonstrating how to use the optical module of Setfos in order to demonstrate how much the color point of a full OLED can be tuned for a given emitter spectrum. Moreover, we compare the efficiency of the color-optimized device with the one that is tuned for the highest outcoupling/radiance and analyze the consequent trade-off between color purity and efficiency.
The same analysis and optimization can be performed for other types of emitters such as quantum dots or perovskites. Despite the narrow emission spectra of these emitters, the optics of such QLEDs and PeLEDs is equal to the well-established OLEDs.
Check the full discussion here: https://www.fluxim.com/optimization-of-a-blue-oled-cavity
Read MoreOur 2D + 1D software LAOSS is a perfect tool to understand and improve on different upscaling strategies which combine 1D layer stack with 2D lateral simulations. In this blog post, we will discuss the findings by Matthias Diethelm and his colleagues who used LAOSS to simulate centimeter-sized organic solar cells to understand loss channels and macroscopic defects.
Read the full post here www.fluxim.com/electro-thermal-modeling-of-thin-film-solar-cells
Read MoreFLUXiM is a provider of device simulation software and characterization platforms to the display, lighting, photovoltaics and electronics industries worldwide.
