Contact:

Project title: Electroluminescent devices based on ionic transition metal complexes 
Researcher: Giulia Longo

Supervisor: Dr. Hendrik Bolink

Project description

Objectives:
Design of electronic, ionic charge transporting and light emitting materials that can be processed into thin films using solution based techniques leading to photoluminescence quantum yields higher than 50%.
Development of solution processable light-emitting devices employing ionic transition metal complexes, having a power efficiency in excess of 25 lumen/Watt.
Set-up a technique that enables the determination of the ionic conductivities in the thin film structures.
Tasks and methodology:
Selection of iTMC with a high photoluminescence quantum yield in solution (jointly with P6). Optimization of thin film morphology by incorporation of suitable ionic materials, both small molecular weight and polymeric.
Integration of the solution processed thin films into single and multilayer devices in a clean room environment.
 Use transient techniques to establish the current density originating from ionic motion in the solid films.

Secondment: OSRAM GmbH, Germany

Achievements:

Papers
1. C. Roldán-Carmona, O. Malinkiewicz, R. Betancur, G. Longo, C. Momblona, F. Jaramillo, L. Camacho, H. J. Bolink, “High efficiency single-junction semitransparent perovskite solar cells”, Energy environ. Sci, 7, (2014), 2968-2973.
2. S. Keller, E. C. Constable, C. E. Housecroft, M. Neuburger, A. Prescimone, G. Longo, A. Pertegás, M. Sessolo, H. J. Bolink, “[Cu(bpy)(P^P)]+ containing light-emitting electrochemical cells: improving performance through simple substitution”, Dalton Trans., 43, (2014), 16593-16596.
3. L. Gil-Escrig, G. Longo, A. Pertegás, C. Roldán, A. Soriano Portillo, M. Sessolo, H. J. Bolink, “Efficient photovoltaic and electroluminescent perovskite devices”, Chem. Commun., 51, (2015), 569-571.
4. N. Kaihovirta, G. Longo, L. Gil-Escrig, H. J. Bolink, L. Edman, “Self-absorption in a light-emitting electrochemical cell based on an ionic transition metal complex”, Appl. Phys. Lett., 106 (2015), 103502.
5. G. Longo, L. Gil-Escrig, M. Degen, M. Sessolo, H. J. Bolink, “Perovskite solar cells prepared by flash evaporation”, Chem. Commun., 51, (2015), 7376-7378.
6. A. M. Bünzli, E. C. Constable, C. E. Housecroft, A. Prescimone, J. A. Zampese, G. Longo, L. Gil-Escrig, A. Pertegás, E. Ortí, H. J. Bolink, “Exceptionally long-lived light-emitting electrochemical cells: multiple intra-cation π-stacking interactions in [Ir(C^N)2(N^N)][PF6] emitters”, Chem. Sci., 6, (2015), 2843-2852.
7. G. Longo, A. Pertegás, L. Martínez-Sarti, M. Sessolo, H. J. Bolink, “Highly luminescent perovskite-aluminium oxide composites”, J. Mater. Chem. C, 3, (2015), 11286-11289.

Conferences
1. G. Longo, C. Roldán, C. Momblona, O. Malinkiewicz, H. Bolink, “Evaporated top electrodes for high efficiency single junction semitransparent solar cells”, 2^nd Organic OptoElectronic International Summer School, June 2-6, 2014, Bouthéon (France)
2. C. Roldán, O. Malinkiewicz, G. Longo, C.Momblona, H.Bolink, “Metal-oxide free perovskite solar cells: high efficient, flexible and semitransparent devices”, 6th International Conference on Hybrid and Organic Photovoltaics  May 11-14, 2014, Lusanne (Switzerland)

LUMINET meetings :

LUMINET Autumn Meeting, September 2014, Ausburg, Germany
LUMINET Spring Meeting, 3-6 March 2015, Verona, Italy
LUMINET Autumn Meeting, 25 September 2015, Tartu, Estonia
LUMINET Spring Meeting, 21-22 March, Aveiro, Portugal