Influence of emissive layer thickness on electrical characteristics of polyfluorene copolymer based polymer light emitting diodes

India-Japan Expert Group Meeting on Biomolecular Electronics & Organic Nanotechnology for Environment Preservation

物理学;生物科学;生态环境科学

Das, D.^1 ; Gopikrishna, P.^1 ; Singh, A.^1 ; Dey, A.^1 ; Iyer, P.K.^1,2

Centre for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati, Assam

781039, India^1

Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam

781039, India^2

关键词: Device configurations;    Electrical characteristic;    Impedance spectroscopy;    Parallel capacitance;    Parallel resistance;    Polyfluorene copolymer;    Polymer light emitting diode;    Polymer light-emitting diodes;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/704/1/012016/pdf
DOI  :  10.1088/1742-6596/704/1/012016

来源: IOP

【 摘 要 】

Polymer light emitting diodes (PLEDs) with a device configuration of ITO/PEDOT:PSS/PFONPN01 [Poly [2,7-(9,9'-dioctylfluorene)-co-N-phenyl-1,8-naphthalimide (99:01)]/LiF/Al have been fabricated by varying the emissive layer (EML) thickness (40/65/80/130 nm) and the influence of EML thickness on the electrical characteristics of PLED has been studied. PLED can be modelled as a simple combination of resistors and capacitors. The impedance spectroscopy analysis showed that the devices with different EML thickness had different values of parallel resistance (RP) and the parallel capacitance (CP). The impedance of the devices is found to increase with increasing EML thickness resulting in an increase in the driving voltage. The device with an emissive layer thickness of 80nm, spin coated from a solution of concentration 15 mg/mL is found to give the best device performance with a maximum brightness value of 5226 cd/m2.