The Investigation On Perovskite Solar Cells With Organic Polymers Via Molecularly P-Type Doping

In the past few years,the photovoltaic community has witnessed a rapid emergence of a new class of solid-state heterojunction solar cells based on solution-processable organometal halide perovskite absorbers.The energy conversion efficiency of solid-state perovskite solar cells(PSCs)has been quickly increased to 22.1% so far.Perovskites materials have shown several unique characteristics,such as a broad spectral absorption range,large absorption coefficient,high charge carrier mobility and diffusion length.Hole-transporting materials(HTMs),which are essential components in PSCs,play a key in extraction and collection of photogenerated holes and transporting these charges to the metal electrode.Conducting polymer P3 HT as a model complex has been widely researched in photovoltaic devices,while pristine P3HT-based PSCs couldn’t reach to a high performance so far.Carriers transporting ability of P3 HT is the key point for efficient PSCs as p-type doping provide a theoretical method for reinforcing the electrical properties.Herein,we introduce a simple molecular p-type dopant F4 TCNQ for P3HT(1.0%,w/w).This composite based HTM exhibits an impressive power conversion efficiency of 14.4% that higher than both native and traditional LiTFSI and TBP doping P3 HT PSCs.Meanwhile,the long-term stability has also been improved owing to abandon hydroscopic doping materials and corrosive solvent.In addition,we successfully introduced F4 TCNQ as an efficient p-type dopant for donoracceptor(D-A)co-polymer PCPDTBT as a HTM in mesoscopic PSCs.The bulk conductivity was significantly enhanced by 4 orders of magnitude when PCPDTBT is doped with F4TCNQ(6%,w/w).Spectroscopic results indicate the occurrence of p-doping,which resulted in higher bulk conductivity.The high conductivity leads to an impressive overall efficiency of 15.1%,which is considerably higher than the pristine PCPDTBT-based devices.The superior performance obtained should be largely attributed to the significant enhancement of the photocurrent density,which is strongly correlated with a more efficient charge collection.This is the highest efficiency reported so far for PCPDTBT-based PSCs.Meanwhile,hydrophobic PCPDTBT:F4TCNQ film also guaranteed the long-term stability of PSCs.Molecularly pdoping was thus demonstrated to be an effective strategy for further improving the performance of organic polymeric HTMs in PSCs.