2021 delivered a series of records in Power Conversion Efficiency for Emerging PVs. The year finished out with impressive results from Prof. Steve Albrecht’s Group, HZB (DOI: 10.1126/science.abd4016). At the current rate of development, the 30% efficiency barrier for a Pero/Si tandem cell may well be broken in 2022. The efficiency race certainly makes for great headlines, but there is also the limited device stability that needs to be overcome to win the day. In 2021, we have seen great steps forward here too. We are proud to see our tools supporting this development.

NREL emerging solar cell efficiency chart

The Future for Light Emitting Diodes (LEDs)

The OLED market is often thought of as mature. After all, there are a plethora of displays available now using this technology. However, the research field is far from in decline. As displays and devices evolve (think AR, automotive displays, large-area lighting, flexible screens) the demand to develop better device performance increases. It’s in the R&D labs that this work will be done. We’re expecting some strong results this year on OLEDs, but also on Perovskite LEDs and QDLEDs. We’ll be sure to share the latest results from our customers so watch this space.

What could Fluxim deliver to help your research in 2022?

Over the years we have developed a comprehensive tool kit that enables researchers rapid validation of their work through simulation and characterization. If you’ve been following our monthly posts you’ll be up to date with the benefits of using Setfos, Laoss, and Paios. We have another instrument called PHELOS. This is what we are going to present today.

Electroluminescence (EL) and Photoluminescence (PL) Spectroscopies are fundamental for the development of Perovskite LEDs, Quantum Dot LEDs, QD-Films, and OLEDs. Advanced PL and EL characterization are performed with respect to the emission angle and the polarization. We developed the tabletop instrument Phelos to combine these techniques and although we could write many paragraphs as to the benefits of using this all-in-one Gonio-spectrometer we’ve prepared a short film to do the same. Enjoy.

Who is using Phelos?

Phelos is relatively new but has proven popular with several research groups. When their work is published and our tools have been part of their research then naturally we are super pleased and want to share it. Here are few selected papers:

Optical Outcoupling Efficiency of Organic Light-Emitting Diodes with a Broad Recombination Profile

Yungui Li, Naresh B. Kotadiya, Bas van der Zee, Paul W. M. Blom, and Gert-Jan A. H. Wetzelaer

Adv. Optical Mater. 9, 2001812, (2021)

https://onlinelibrary.wiley.com/doi/full/10.1002/adom.202001812

The Max Planck researchers developed a numerical model to simulate the fraction of photons coupled to air for OLEDs with a broad recombination zone. The simulation was also demonstrated experimentally with a single-layer OLED fabricated with the TADF emitter 9,10-bis(4-(9H-carbazol-9-yl)-2,6-dimethylphenyl)-9,10-diboraanthracene (CzDBA).

The dipole orientation of the CzDBA film was determined by measuring the angle-dependent PL with Phelos and by fitting the data with the simulation software Setfos.

Scalable photonic sources using two-dimensional lead halide perovskite superlattices

Jakub Jagielski, Simon F. Solari, Lucie Jordan, Declan Scullion, Balthasar Blülle, Yen-Ting Li, Frank Krumeich, Yu-Cheng Chiu, Beat Ruhstaller, Elton J. G. Santos and Chih-Jen Shih

Nature Communications 11, 387 (2020)

https://www.nature.com/articles/s41467-019-14084-3

The authors fabricated decoupled multi-quantum-well superlattices comprised of colloidal quantum wells of lead halide perovskites, with unprecedentedly ultrathin quantum barriers. Crystallographic and 2D k-space spectroscopic analyses reveal that the transition dipole moment orientation of bright excitons in the superlattices is predominantly in-plane and independent of the stacking layer and quantum barrier thickness, confirming interlayer decoupling.

Phelos was used to perform angle-dependent photoluminescence to determine the emitter orientation.

Kinetic Control over Self-Assembly of Semiconductor Nanoplatelets

Rebecca Momper, Heng Zhang, Shuai Chen, Henry Halim, Ewald Johannes, Stoyan Yordanov, Daniele Braga, Balthasar Blülle, David Doblas, Tobias Kraus, Mischa Bonn, Hai I. Wang, and Andreas Riedinger

Nano Letters 6, 4102, (2020)

https://pubs.acs.org/doi/10.1021/acs.nanolett.9b05270

Our team collaborated with the Max Plank Institute to demonstrate that collective nanoplatelets’ orientation can be controlled at the millimeter scale by engineering the solvent evaporation at the liquid-liquid interface where the crystallization occurs. The ability to kinetically control the assembly of nanoplatelets into ordered monolayers with tunable optical and electronic properties paves the way for new applications in optoelectronic devices. Phelos was used to measure the angle-dependent photoluminescence of the CdSe Nanoplates, whereas Setfos was used to fit the experimental data and extract the orientation of the dipoles.

Read further research enabled with Phelos >

We are coming to a conference near you!

Online conferences have been very useful during the pandemic. They’ve enabled us all to stay in contact and share our work. But let’s face it they have their limitations. We’ve missed the excitement of meeting friends and collaborators from past research projects and of course the opportunity to make new connections in the LED and solar cell communities. The ability to travel is improving and so we’ve filled out our conference calendar for the year ahead and we are hopeful that we’ll be able to attend them all in person.

If you’d like to meet with us and discuss what’s new with our research tools or attend one of our researcher’s oral presentations here’s where we’ll be in 2022: