Developing the next generation of solar cells or LEDs requires fast and reliable characterization tools
/Generally, a comprehensive characterization of a solar cell or an LED is performed by using several different techniques, which requires moving the sample on different setups. This “classical research approach” doesn't cut it when you are dealing with materials that can degrade fast, such as organic semiconductors or perovskites. Also, using a rack of different instruments and switching in between them slows down your research, and gives rise to systematic measurement errors.
These problems inspired us to develop a single all-in-one characterization tool that contains all the optoelectrical characterization techniques you need.
This tool is called Paios.
Paios was first developed in 2012 to serve the OLED and OPV communities. Since then it has been developed alongside the needs of researchers working on several next-generation solar cells, LEDs, and batteries. Devices based on organic, perovskite, and quantum-dots are only an example of what you can study with PAIOS.
Current-Voltage-Luminance
Transient Photocurrent (TPC)
Transient Photovoltage (TPV)
Transient Electroluminescence
Charge Extraction
Dark and Photo-CELIV
DLTS
Impedance Spectroscopy
Capacitance-Voltage
IMPS/IMVS
Modulated Electroluminescence Spectroscopy (MELS)
Emission Spectrum Analysis
User-defined characterization routines
Recent Results Obtained with Paios
Chain Conformation Control of Fluorene-Benzothiadiazole Copolymer Light-Emitting Diode Efficiency and Lifetime
Bingjun Wang, Donal D. C. Bradley, et al.
ACS Applied Materials & Interfaces Article ASAP (Jan 2021)
https://pubs.acs.org/doi/abs/10.1021/acsami.0c18490
The aim of this research was to fabricate efficient OLEDs with poly(9,9-dioctylfluorene) (PFO) as an emissive layer, by controlling the formation of its beta-phase. The latter was proven to increase the performance of PFO-based OLEDs. The goal was achieved by using the copolymer 90F8:10BT. The 5% ordered film shows improved efficiency and lifetime compared to the 0% beta-phase Polymer LED.
Paios was used to perform steady-state/transient EL measurements and MIS-CELIV. These measurements helped to prepare samples with a more balanced electron and hole charge transport.
Ultra‐Low Dark Current Organic-Inorganic Hybrid X‐Ray Detectors
M. Prabodhi A. Nanayakkara, S. Ravi P. Silva et al.
Adv. Funct. Mater. 2020, 2008482
https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202008482
One step further towards a commercial X-ray detector based on organic semiconductors. The team of Professor Ravi Silva at the University of Surrey developed a hybrid X-ray detector with bismuth oxide nanoparticles incorporated into an organic bulk heterojunction. The key feature of such devices is the low dark current, which is fundamental to detect low dose rates and to have a good dynamic range.
Their hybrid organic-inorganic X-ray detectors have the lowest dark currents reported so far. Such features make them suitable for imaging and dosimetry in medical and industrial applications.
The research team used Paios to perform photo-CELIV, impedance spectroscopy, TPV, and TPC. They extracted fundamental material parameters, such as the charge transport mobility and the recombination lifetime.
With further development, the device response characteristics can be comparable to conventional X-ray detectors, with the added benefit of being flexible and cheaper.
A Multilayered Electron Extracting System for Efficient Perovskite Solar Cells
Akmaral Seitkhan, Iain McCulloch, et al.
Adv. Funct. Mater. 2020, 2004273
https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202004273
A new Electron Transport Layer (ETL) that boosts the efficiency of perovskite solar cells up to 19.2% has been developed by Kaust.
The ETL in a pero-PV needs to assure good charge transport with reduced recombination losses and suitable energy level alignment with the perovskite and the electrode. The group of Prof. McCulloch and colleagues at the Kaust Solar Centre proposed a solution-processable trilayer of PC60BM, Al-doped zinc oxide (AZO), and triphenyl-phosphine oxide (TPPO), which meets this expectation.
This ETL improved the power conversion efficiency (PCE) by around 3% with respect to a control structure with PC60BM-only. The fill factor (FF) of the best device was 82% and the device stability under constant illumination was around 800 h.
Paios helped them demonstrating that the improved charge extraction and higher carrier lifetime are due to the reduced trap-assisted recombination. This all-in-one platform was used to perform several opto-electrical characterizations, such as Transient Photocurrent (TPC), Capacitance-Voltage (CV), Charge Extraction (CE), and Light-Intensity-Dependent Measurements.
Research Fields
Paios can be employed to characterize different types of devices based on organic semiconductors, perovskites and quantum-dots:
Perovskite solar cells
Organic, quantum dot, and hybrid solar cells
CIGS, CdTe, CZTS solar cells
Dye-sensitized solar cells
Solid-state thin-film batteries
Organic light-emitting diodes (OLEDs)
Perovskite-LEDs and QD-LEDs
Light-emitting electrochemical cells (LECs)
Monopolar devices
Metal-Insulator Semiconductor (MIS) devices
What researchers are saying about Paios
"The automated measurement platform Paios allows one to perform a series of measurements on organic solar cells within a matter of minutes, which otherwise would have taken days"
Tom van der Hofstad, Eindhoven University of Technology, The Netherlands
"We successfully characterized the transient response of silicon-based solar cells with the Paios measurement system. For instance, we were able to determine the electron mobility and photo-carrier lifetime."
Prof. Dr. Seung Jae Baik, Korea Advanced Institute of Science and Technology (KAIST), South Korea
The new version of the Characterization Suite is here
We are proud to announce the release of the Characterization Suite 4.3.1! This software update contains a range of improvements and new features for Paios, Phelos, and Litos.
- The new Dipole Orientation Fit can be used for angular PL data obtained with Phelos. It allows determining the emitter orientation in a material directly by performing the data fitting within the CS Graphical User Interface (GUI). We also added the two-diode-model fit as postprocessing for dark JV curves.
- Paios now allows characterizing electrochemical devices such as thin-film batteries. Several experiments, such as cyclovoltammetry, impedance spectroscopy, and charge-discharge, can now be performed systematically with Paios.
- We have further improved the Nanosecond Pulser module (extension for the automatic measurement table of Paios) which can now also be ordered with a UV LED.
- We are proud to release officially the software extension for our system Litos for OLED. This instrument can be equipped for top- or bottom-emitting devices and can integrate photodiodes and spectrometers to measure the emission intensity and spectrum in-situ during degradation. Similar to Litos for solar cells, each of the up to 32 pixels can be stressed independently, and each chamber has its own temperature control. It is also possible to perform intermediate Paios routines on all pixels inside Litos.
