A study of the effect of figure of merit on the performance of FTO based organic light emitting diode (OLED)
Dhrubajyoti Saikia and R Sarma
In our work green organic Light Emitting Diodes have been fabricated and we study their J-V-L performances. Here N,N’-bis ( 3- methyl phenyl )- N, N’ ( phenyl )-benzidine( TPD) is used as hole transport layer(HTL) and Tris( 8-hydroxy quinolinato) aluminium (Alq3) as both emitting layer and electron transport layer(ETL). The performance of the devices explains on the basis of figure of merit (FOM) which is the function of optical transmittance and sheet resistance. The range of thicknesses of hole transport layer is 10nm-50nm and that of emissive layer is 15nm-70nm respectively. Here high luminance has been obtained at the operating voltage less than 20 volt with turn-on voltage 6.7 volt. The performances of the devices are studied by J-V and L-V characteristics. With a combination of 30nm HTL and 44nm ETL organic layer thickness, better charge balancing is achieved and luminous efficiency is maximum. This bilayer organic film provides maximum luminance greater than 2500 Cd/m2 with a current density 144 mA/cm2.