High charge mobility in two-dimensional percolative networks of PbSe quantum dots connected by atomic bonds

Two-dimensional networks of quantum dots connected by atomic bonds have an electronic structure that is distinct from that of arrays of quantum dots coupled by ligand molecules. We prepared atomically coherent two-dimensional percolative networks of PbSe quantum dots connected via atomic bonds. Here, we show that photoexcitation leads to...

Highly efficient carrier multiplication in PbS nanosheets

Semiconductor nanocrystals are promising for use in cheap and highly efficient solar cells. A high efficiency can be achieved by carrier multiplication (CM), which yields multiple electron-hole pairs for a single absorbed photon. Lead chalcogenide nanocrystals are of specific interest, since their band gap can be tuned to be optimal to exploit...

Disorder strongly enhances Auger recombination in conductive quantum-dot solids

Auger recombination (AR) can be an important loss mechanism for optoelectronic devices, but it is typically not very efficient at low excitation densities. Here we show that in conductive quantum-dot solids, AR is the dominant charge carrier decay path even at excitation densities as low as 10?3 per quantum dot, and that AR becomes faster as the...

High charge-carrier mobility enables exploitation of carrier multiplication in quantum-dot films

Carrier multiplication, the generation of multiple electron–hole pairs by a single photon, is of great interest for solar cells as it may enhance their photocurrent. This process has been shown to occur efficiently in colloidal quantum dots, however, harvesting of the generated multiple charges has proved difficult. Here we show that by tuning...