Hole transfer from PbS nanocrystal quantum dots to polymers and efficient hybrid solar cells utilizing infrared photons

► Hole transfer from PbS nanocrystals to p-type polymers was first observed. ► A type-II heterojunction was formed between the PbS nanocrystals and PCPDTTBTT. ► The polymer-PbS nanocrystal heterojunction solar cell exhibits a record PCE of 3.80%. ► The photocurrent has an extended spectral range spanning from the UV to the IR. ► Contributions from the polymer and PbS to the photocurrent were identified.