Incorporation of black phosphorus into P3HT: PCBM/n-type Si devices resulting in improvement in electrical and optoelectronic performances

The effect of the incorporation of black phosphorus (BP) into poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM) on the electrical conduction mechanisms in the rectifying current–voltage characteristics of P3HT:PCBM/n-type Si devices was investigated. It is found that the forward-voltage currents are limited by thermionic emission mechanism. The incorporation of BP into P3HT:PCBM leads to a combined effect of a reduction in resistivity and an increase in the surface roughness, resulting in improvement in the electrical and optoelectronic performances of P3HT:PCBM/n-type Si devices. The findings show that high responsivity originates from the external light injection efficiency, internal power conversion efficiency, and carrier collection.