The Effect Of Built-in Field On The Interfacial Exciton Recombination And Dissociation In N-N Type Organic Solar Cells

The fundamental physics processes of photocurrent generation in small molecular organic solar cells have been studied in our research. The N-N type of organic solar cells has been used to study the exciton dissociation and exciton recombination at the D/A interface, the effect of built-in electric field direction on photocurrent generation also have been studied. Our effort focused on two parts:1. The performance of exciton recombination process generating photocurrent was studied in N-N type small organic solar cellsThe performance of exciton recombination process was studied at the F16ZnPc/C60and C60/F16ZnPc interfaces, by measuring the absorption spectrum and the IPCE (internal photon to current efficiency) to find the contribution of photocurrent from F16ZnPc and C60.The performance of superliner dependence between photocurrent and light intensity (n>1) further confirmed the existence of exciton recombination.2. The built-in electric field effect the generation processes of photocurrentThe photocurrent solely comes from exciton recombination in device A (ITO/Mo03/F16ZnPc/C6o/Alq3/Al), while the photocurrent comes from exciton dissociation and exciton recombination in device B (ITO/F16ZnPc/C60/Alq3/MoO3/Al). The different of A and B is the direction of built-in electric field. By controlling the direction of built-in electric field at the F16ZnPc/C60interface, the processes of photocurrent generation can be altered.