PERovskIte Coherent Light Sources

Project Information

PERICLeS

Grant agreement ID: 839480

DOI

10.3030/839480

Project closed

EC signature date 27 March 2019

Start date 1 September 2020

End date 31 August 2022

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 183 473,28

EU contribution

€ 183 473,28

Coordinated by

FONDAZIONE ISTITUTO ITALIANO DI TECNOLOGIA
Italy

Periodic Reporting for period 1 - PERICLeS (PERovskIte Coherent Light Sources)

Reporting period: 2020-09-01 to 2022-08-31

Summary of the context and overall objectives of the project

The action has developed metal halide perovskite semiconductors as innovative gain media towards the realization of solution-processable laser diodes. This type of device represents a breakthrough for the realization of a new disruptive technology of cost-effective, flexible lasers that are compact, easily scalable and with wide spectral tunability. Nevertheless, due to intrinsic limitations of transport and luminescence of standard organic materials, the fabrication of organic diode lasers has so far remained elusive. Thanks to the ideal optoelectronic properties and synthetic versatility, metal halide perovskites hold great promises for the realization of electrically pumped lasers: this project as studied the compositional and structural engineering of these materials to reach a perfect balance between efficient radiative recombination, long radiative lifetime and high
mobility and meet the requirements to reach this target.

The project has a significant societal impact, as its outcomes have direct influence on the fabrication of both incoherent and coherent light sources with properties beyond the state-of-the-art of current semiconductors, representing a key enabling technology for advanced multiband photonic platforms and lab-on-a-chip systems.

The main objectives of the action are:
1) Design and synthesize advanced functional perovskites with high luminescence quantum yield and optimal charge transport.
2) Photophysical characterization of the material and its integration in a laser resonator.
3) Integration of perovskite/resonator system in electroluminescent devices.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

1) Perovskite doping for the development of 4-level systems. Europium (III) and Yb (III) doping has been performed by means of direct substitutional doping or by intercalation of metal-organic lanthanide complexes. An innovative doping strategy was developed combining Eu(III) with naphtylmethylammonium as functional templating cation assisting the energy transfer from the perovskite to the lanthanide. Spectral tuning, enhancement of luminescence quantum yield and integration in light emitting devices have been achieved.

2) Impact of templating cations on lasing properties of layered perovskites. Tin perovskites have been developed as a viable lead-free platform, finding that they posses superior optical gain properties compared to the layered Pb-based counterparts. We observed that the templating cation plays a critical role in determining the crystallinity and defectivity of the material, in turn affecting the lasing characteristics. Upon proper synthetic design, we were able to demonstrate lasing in layered tin perovskites integrated with an optical resonator.

3) Effect of structural design on the optical gain of multidimensional perovskites. By combining the variable stripe-length (VSL) method and transient absorption, we have investigated the multi-excitonic interactions at high excitation densities and show that the modulation of the steric hindrance and fluorination of the templating cation plays a fundamental role on the optical gain properties, amplified spontaneous emission (ASE) threshold and operational stability. A dramatic impact is found on the optical gain coefficient, reaching a maximum of 1000 cm-1 in optimized compositions and showing a difference of two orders of magnitude depending on the templating cation, in turn affecting the carrier density at which ASE is observed.

4) Processing optimization of formamidinium (FA) and cesium-based lead perovskites and investigation of their structure-properties relationships. Despite showing excellent electroluminescence efficiency, FAPbI3 shows a high ASE threshold which hampers its implementation as coherent emitter. We found that the chemical composition plays a fundamental role to shape its optoelectronic properties, since the addition of bromine enhances the optical gain and improves the electroluminescence efficiency at high current densities, making it an excellent material for laser diodes. Beyond chemical composition, by using CsPbI3 nanocrystals as material platforms and modulating temperature and pressure, we have shown that crystal size and structural deformations have a deep impact on the optoelectronic properties of the material and must be taken into account for the educated design of these materials.

Scientific publications:
D. Cortecchia* et al, Layered perovskite doping with Eu3+ and -diketonate Eu3+ complex, Chem. Mater. 2021, 33, 2289−2297.
A. L. Alvarado-Leaños,D. Cortecchia* et al, Lasing in single-layered 2D tin perovskites, ACS NAno, Just Accepted, https://doi.org/10.1021/acsnano.2c07705
O. Vukovic, A. Petrozza*, D. Cortecchia* et al, Structural effects on the luminescence properties of CsPbI3 nanocrystals, under submission.
C. Soci*, G. Adamo*, D. Cortecchia* et al, Roadmap on perovskite nanophotonics, under submission. (Invited Perspective in Optical Materials: X)
A. L. Alvarado-Leaños, D. Cortecchia et al, Optical gain of lead halide perovskites measured via the variable stripe length method: what we can learn and how to avoid pitfalls, Adv. Opt. Mater. 2021, 2001773.
G. Folpini, M. Palummo, D. Cortecchia et al, Band splitting and plurality of excitons in Ruddlesden-Popper metal halides, ChemRxiv. Cambridge: Cambridge Open Engage; 2021 (Under revision)

Conference presentations:
Synthetic design of metal halide perovskites for photonic applications, Small’s Energy Materials Virtual Symposium, 10 Nov 2020. (Invited Talk)
Low dimensional perovskites: from chemical design to photonic applications, Politecnico di Milano, 18 Feb 2022. (Invited Talk)
Amplified spontaneous emission in single-layerd 2D tin perovskites, MRS2022, Honolulu, May 23-25 2022. (Talk)
Single-layered 2D tin perovskites for lasing applications, Gordon Research Conference (GRC), Ventura, 12-17 Jun 2022. (Poster)

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

1) We have demonstrated a new synthetic strategy that goes beyond the traditional substitutional doping. This consists in the sensitization of the lanthanide dopants in a perovskite matrix assisted by the antenna effect of functional cations, which opens new frontiers for the crystal engineering of functional perovskites. Furthermore, we have shown the possibility to electrically excite lanthanide complexes in the perovskite matrix, thus enabling their application in perovskite light-emitting devices with improved color purity.
2) Lasing in 2D perovskites have been proposed as a promising strategy to improve the radiative recombination efficiency and lower the lasing threshold. However, lasing in these systems have remained allusive and highly debated. For the first time, we have shown that layered tin perovskites can show low threshold lasing. This is a breakthrough discovery that finally enable their exploitation in coherent light sources.
3) We have found that formamidinium-based perovskites, upon proper compositional and processing optimization, can sustain optical gain in LEDs under electrical operation, paving the way for the realization of solution processable laser diodes.

These project’s results will lead to the realization of optoelectronic devices with potentially disruptive impact on medical diagnostics, environmental monitoring, imaging, lighting and communications, providing smart solutions for major societal challenges in healthcare, security, energy efficiency and smart cities.

Representation of a lasing perovskite.