Control of a white organic light emitting diode’s emission parameters using a single doped RGB active layer


Autoria(s): Pereira, Daniel Alfredo de Sá
Contribuinte(s)

Pereira, Luiz

Ferreira, Isabel

Data(s)

17/12/2015

17/12/2015

01/09/2015

01/12/2015

Resumo

White Color tuning is an attractive feature that Organic Light Emitting Diodes (OLEDs) offer. Up until now, there hasn’t been any report that mix both color tuning abilities with device stability. In this work, White OLEDs (W-OLEDs) based on a single RGB blend composed of a blue emitting N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB) doped with a green emitting Coumarin-153 and a red emitting 4-(Dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM1) dyes were produced. The final device structure was ITO/Blend/Bathocuproine (BCP)/ Tris(8-hydroxyquinolinato)aluminium (Alq3)/Al with an emission area of 0.25 cm2. The effects of the changing in DCM1’s concentration (from 0.5% to 1% wt.) allowed a tuning in the final white color resulting in devices capable of emitting a wide range of tunes – from cool to warm – while also keeping a low device complexity and a high stabilitty. Moreover, an explanation on the optoelectrical behavior of the device is presented. The best electroluminescense (EL) points toward 160 cd/m2 of brightness and 1.1 cd/A of efficiency, both prompted to being enhanced. An Impedance Spectroscopy (IS) analysis allowed to study both the effects of BCP as a Hole Blocking Layer and as an aging probe of the device. Finally, as a proof of concept, the emission was increased 9 and 64 times proving this structure can be effectively applied for general lighting.

Identificador

http://hdl.handle.net/10362/16105

Idioma(s)

eng

Direitos

openAccess

Palavras-Chave #White OLED #Emission color tuning #Blend EML #Host:Guest #Color stability #Large area #Domínio/Área Científica::Engenharia e Tecnologia::Engenharia dos Materiais
Tipo

masterThesis