1. Fabrication and characterization of solution processed vertical organic light-emitting device Mohd Arif Mohd Sarjidan 1, a *, Ahmad Shuhaimi 2,b and Wan Haliza Abd Majid 3,c 1,2,3 Low Dimensional Materials Research Centre, Department of Physics, University of Malaya, 50603 Kuala Lumpur, Malaysia a mohd.arif@um.edu.my, b shuhaimi@um.edu.my, c q3haliza@um.edu.my

2. Outline Introduction Objective Experimental Results and discussion Conclusion

3. Introduction What is OLED? a light-emitting diode (LED) in which the emissive electroluminescent layer is a film of organic compound that emits light in response to an electric current. Advantage OLED high contrast wide viewing angle low power consumption low thickness (variety design) low cost (mass-pro) Solution processing Simple Low cost Large area

4. Objective To fabricate single layer OLED via solution process To characterize the fabricated single layer OLED

5. Device fabrication Pre-pattern ITO was cleaned by decon, acetone, IPA, DI. 8mg/mL SPW-111 was prepared in ChCl3 40 nm of PEDOT:PSS was spin-coated on ITO 50nm of SPW-111 was spin-coated on PEDOT:PSS LiF/Al top electrode was thermally deposited

6. Device Characterization Current-voltage-luminance measured by CS-200 Konica Minolta. Voltage from 0 to 10 V. Electroluminescence measured by HR4000CG-UV-NIR Ocean Optic. Voltage from 6 to 10 V Impedance spectroscopy of the devices was measured by using a precision impedance analyzer (Agilent 4294A) Frequency ranging from 10 k to 10 GHz AC signal = 500 mV DC bias= 0, 7 and 10 V

7. I-V-L Analysis  Turn on voltage is 4 V  1000 cd/m2 at 8.5 V

8. EL Analysis  3 EL peaks at 454, 487 and 514 nm  CIE analysis: warm light

9. Impedance Analysis  Mobility carrier can be calculated using:  In order to find t t, the negative differential susceptance –ΔB method has been used [1]. -∆B(ω)= -ω(C-Cgeo)  According to the transit time effect, the maximum value of –ΔB versus frequency plot is constantly occurred at fmax≈ 0.72/tt [2], where tt is a transit time.  Carrier mobility of materials is 2.91×10-6 and 2.54×10-6 cm2 V-1 s-1 at 7 and 10 V, respectively [1] H. C. F. Martens, et. al, Phy. Rev. B 63 (2001) 125328. [2] T. Okachi, et. al, Jpn. J. Appl. Phys. 47 (2008) 8965

10. Conclusion  Single layer OLED has been fabricated by using spin-coating technique.  Electrical and electroluminescence properties of the fabricated OLED was characterized  Warm white emission has been observed for the fabricated OLED with turn of voltage of 4V  Charge carrier mobility of SPW-111 can be obtained by IS measurement. The carrier mobility of materials is 2.51×10- 6 and 3.42×10-6 cm2 V-1 s-1 at 7 and 10 V, respectively