TY - CHAP
T1 - Organic light-emitting diodes (OLEDs)
T2 - Materials, photophysics, and device physics
AU - Adachi, Chihaya
AU - Lee, Saeyoun
AU - Nakagawa, Tetsuya
AU - Shizu, Katsuyuki
AU - Goushi, Kenichi
AU - Yasuda, Takuma
AU - Potscavage, William J.
N1 - Publisher Copyright:
© Springer Japan 2015. All rights reserved.
PY - 2015/9/18
Y1 - 2015/9/18
N2 - Currently, organic light-emitting diodes (OLEDs) have reached the stage of commercialization, and there has been an intense drive to use them in various applications from small-and medium-sized mobile devices to illumination equipment and large television screens. In particular, room-temperature phosphorescent materials have become core OLED components as alternatives to conventionally used fluorescent materials because devices made with phosphorescent materials exhibit excellent light-emitting performance with internal electroluminescence efficiencies (ηint) of nearly 100 %. However, phosphorescent materials have several intrinsic problems, such as being limited to metal-organic compounds containing rare metals, for example, Ir, Pt, Au, and Os, and difficulty in realizing stable blue light emission. As a result, researchers have attempted to develop new materials for use as emissive dopants in OLEDs that overcome these limitations. In this chapter, first we briefly review the progress of OLED materials and device architectures mainly based on fluorescent (first-generation) and phosphorescent (secondgeneration) emitters. Then, we discuss third-generation OLEDs that use a new light-emitting mechanism called thermally activated delayed fluorescence (TADF). Recently, highly efficient TADF, which had been difficult to realize with conventional molecular design, has been achieved by very sophisticated molecular structures, allowing access to the unlimited freedom of molecular design using carbon-based materials. This has led to the production of ultimate OLEDs that are made of common organic compounds without precious metals and can convert electricity to light at ηint of nearly 100 %.
AB - Currently, organic light-emitting diodes (OLEDs) have reached the stage of commercialization, and there has been an intense drive to use them in various applications from small-and medium-sized mobile devices to illumination equipment and large television screens. In particular, room-temperature phosphorescent materials have become core OLED components as alternatives to conventionally used fluorescent materials because devices made with phosphorescent materials exhibit excellent light-emitting performance with internal electroluminescence efficiencies (ηint) of nearly 100 %. However, phosphorescent materials have several intrinsic problems, such as being limited to metal-organic compounds containing rare metals, for example, Ir, Pt, Au, and Os, and difficulty in realizing stable blue light emission. As a result, researchers have attempted to develop new materials for use as emissive dopants in OLEDs that overcome these limitations. In this chapter, first we briefly review the progress of OLED materials and device architectures mainly based on fluorescent (first-generation) and phosphorescent (secondgeneration) emitters. Then, we discuss third-generation OLEDs that use a new light-emitting mechanism called thermally activated delayed fluorescence (TADF). Recently, highly efficient TADF, which had been difficult to realize with conventional molecular design, has been achieved by very sophisticated molecular structures, allowing access to the unlimited freedom of molecular design using carbon-based materials. This has led to the production of ultimate OLEDs that are made of common organic compounds without precious metals and can convert electricity to light at ηint of nearly 100 %.
KW - Electroluminescence
KW - OLED
KW - TADF
UR - http://www.scopus.com/inward/record.url?scp=84956679376&partnerID=8YFLogxK
U2 - 10.1007/978-4-431-55654-1_2
DO - 10.1007/978-4-431-55654-1_2
M3 - Chapter
AN - SCOPUS:84956679376
SN - 9784431556534
SP - 43
EP - 73
BT - Organic Electronics Materials and Devices
PB - Springer Japan
ER -