Enhancing The Efficiency of White Organic Light-emitting Diode Using Energy Recyclable Photovoltaic Cells

We demonstrate that power recycling is feasible by using a semi-transparent stripped Al electrode as interconnecting layer to merge a white organic light-emitting devices(WOLED) and an organic photovoltaic(OPV) cell.The device is called a PVOLED.It has a glass / ITO / CuPc / m-MTDATA ∶ V 2 O 5 / NPB / CBP ∶ FIrpic ∶ DCJTB / BPhen / LiF / Al / P3HT∶ PCBM / V 2 O 5 / Al structure.The power recycling efficiency of 10.133% is achieved under the WOLED of PVOLED operated at 9 V and at a brightness of 2 110 cd / m 2,when the conversion efficiency of OPV is 2.3%.We have found that the power recycling efficiency is decreased under high brightness and high applied voltage due to an increase input power of WOLED.High efficiency(18.3 cd / A) and high contrast ratio(9.3) were obtained at the device operated at 2 500 cd / m 2 under an ambient illumination of 24 000 lx.Reasonable white light emission with Commission Internationale De L’Eclairage(CIE) color coordinates of(0.32,0.44) at 20 mA / cm 2 and slight color shift occurred in spite of a high current density of 50 mA / cm 2.The proposed PVOLED is highly promising for use in outdoors display applications.