Solution-Processed Black Phosphorus/PCBM Hybrid Heterojunctions for Solar Cells
Inorganic–organic hybrid structures have become promising candidates for the fabrication of solar cells, owing to easy preparation and integrated advantages of both components. Black phosphorus (BP), an emerging two dimensional inorganic material, has recently attracted great attention particularly in the field of semiconducting devices, due to its intrinsic characters in tunable bandgap, efficient charge transport and superior conducting property. However, its poor stability, uncontrollable morphology and high-density charge traps have largely limited its further development and engineering for efficient photovoltaic devices. Herein, we presented two sheet-shape hybrid heterojunctions using BP/PCBM (PCBM = phenyl-C61-butyric acid methyl ester) prepared in solution process and explored their performance in solar cells. The well-prepared hybrid heterojunctions (layered stacking structure and doping-weaving structure) with uniform hexagonal shape exhibited favorable optical and thermal stability. More importantly, the average power conversion efficiency (PCE) of solar cells reached to 6.4% using the hybrid with the layered stacking structure, and 8.0% for the hybrid with the doping-weaving structure. The present work is the first example of combining BP and PCBM to form heterojunctions for highly efficient solar cells, which may open up a promising route for promoting photovoltaic research.