Platinum (tetraphenylbenzylporphyrin) as an efficient donor layer in organic photovoltaics

M. DOLORES PEREZ; CARSTEN BOREK; PETER I. DJUROVICH; ELIZABETH I. MAYO; RHONDA BAILEY-SALZMAN; STEPHEN R. FORREST; MARK E. THOMPSON

San Francisco, CA

Congreso; 2008 MRS Spring Meeting; 2008

Metalated porphyrins are known to be very strong absorbers in the visible region and little has been explored in their application as materials for solar conversion in solid state organic photovoltaics. In this work, platinum (tetraphenylbenzylporphyrin) (PtTPBP) has been introduced as donor layer in typical planar heterojunction architecture solar cell using C60 as acceptor and BCP as buffer layer. Despite its non planar shape, the optimized cell performs rather efficiently resulting in a higher Voc, and efficiency, than that of the more thoroughly studied CuPc/C60/BCP cell. One added advantage of this compound is its high solubility in organic solvents which allows the possibility of applying the donor layer by spin coating onto the ITO substrate. This new avenue has not been heavily explored in the field of small molecule organic solar cells and would allow for easier and cheaper processing and fabrication of the devices. Devices using this technique perform reasonably well with high FF but a lower efficiency compared to the all vapor deposited counterpart, indicating that packing and morphology of the donor differs from both techniques hence affecting the performance of the device.