Chapter 13
Design of Circularly Polarized Thermally
Activated Delayed Fluorescence Emitters
Gregory Pieters and Lucas Frederic
Abstract This chapter focuses on the molecular designs of Small Organic Molecules (SOM) merging Circularly Polarized Luminescence (CPL) and Thermally
Activated Delayed Fluorescence (TADF) properties. In Introduction, the benefits
associated with the combination of these properties into SOM for their application as
emitting materials to construct Circularly Polarized Organic Light Emitting Diodes
(CPOLED) are presented. Next, the different molecular designs leading to CPTADF
SOM are described depending on the nature of the chirality of these molecules
(point, axial, or planar chirality). The synthesis, photophysical, and chiroptical
properties of these molecules and the performance of related CPOLED devices are
discussed.
13.1 Introduction
Among all the potential applications of Circularly Polarized Luminescent active
Simple Organic Molecules (CPL-SOMs), their use as emitters in Organic Light
Emitting Diodes (OLED) is one of the most exciting applications. Indeed, the
development of CP-OLED has emerged as an interesting direction to substantially
increasing the energy efficiency of conventional OLED displays in which 50% of the
light emitted is suppressed using a polarizer and a quarter-wave plate to reduce the
external light reflection [1, 2]. This high energy loss can be overcome by using
CP-OLED which generates circularly polarized electroluminescence that can pass
through these filters without any attenuation, resulting in higher display performances in terms of autonomy and contrast. Although this type of device presents
undeniable advantages over conventional OLED, described examples are still rare in
the literature [3]. Among those research works, chiral lanthanides [4, 5] and
cholesteric-based [6–8] CP-OLED devices have shown high degree of circular
polarized electroluminescence (g El up to 1 and 1.6 for lanthanide and cholesteric
G. Pieters (*) · L. Frederic
Université Paris Saclay, SCBM, CEA Paris Saclay, Gif-sur-Yvette, France
e-mail: gregory.pieters@cea.fr; lucas.frederic@cea.fr
© Springer Nature Singapore Pte Ltd. 2020
T. Mori (ed.), Circularly Polarized Luminescence of Isolated Small Organic
Molecules, https://doi.org/10.1007/978-981-15-2309-0_13
293
Design of Circularly Polarized Thermally
Activated Delayed Fluorescence Emitters
Gregory Pieters and Lucas Frederic
Abstract This chapter focuses on the molecular designs of Small Organic Molecules (SOM) merging Circularly Polarized Luminescence (CPL) and Thermally
Activated Delayed Fluorescence (TADF) properties. In Introduction, the benefits
associated with the combination of these properties into SOM for their application as
emitting materials to construct Circularly Polarized Organic Light Emitting Diodes
(CPOLED) are presented. Next, the different molecular designs leading to CPTADF
SOM are described depending on the nature of the chirality of these molecules
(point, axial, or planar chirality). The synthesis, photophysical, and chiroptical
properties of these molecules and the performance of related CPOLED devices are
discussed.
13.1 Introduction
Among all the potential applications of Circularly Polarized Luminescent active
Simple Organic Molecules (CPL-SOMs), their use as emitters in Organic Light
Emitting Diodes (OLED) is one of the most exciting applications. Indeed, the
development of CP-OLED has emerged as an interesting direction to substantially
increasing the energy efficiency of conventional OLED displays in which 50% of the
light emitted is suppressed using a polarizer and a quarter-wave plate to reduce the
external light reflection [1, 2]. This high energy loss can be overcome by using
CP-OLED which generates circularly polarized electroluminescence that can pass
through these filters without any attenuation, resulting in higher display performances in terms of autonomy and contrast. Although this type of device presents
undeniable advantages over conventional OLED, described examples are still rare in
the literature [3]. Among those research works, chiral lanthanides [4, 5] and
cholesteric-based [6–8] CP-OLED devices have shown high degree of circular
polarized electroluminescence (g El up to 1 and 1.6 for lanthanide and cholesteric
G. Pieters (*) · L. Frederic
Université Paris Saclay, SCBM, CEA Paris Saclay, Gif-sur-Yvette, France
e-mail: gregory.pieters@cea.fr; lucas.frederic@cea.fr
© Springer Nature Singapore Pte Ltd. 2020
T. Mori (ed.), Circularly Polarized Luminescence of Isolated Small Organic
Molecules, https://doi.org/10.1007/978-981-15-2309-0_13
293