title: Enhanced hot-carrier cooling and ultrafast spectral diffusion in strongly coupled PbSe quantum-dot solids.
abstract: PbSe quantum-dot solids are of great interest for low cost and efficient photodetectors and solar cells. We have prepared PbSe quantum-dot solids with high charge carrier mobilities using layer-by-layer dip-coating with 1,2-ethanediamine as substitute capping ligands. Here we present a time and energy resolved transient absorption spectroscopy study on the kinetics of photogenerated charge carriers, focusing on 0-5 ps after photoexcitation. We compare the observed carrier kinetics to those for quantum dots in dispersion and show that the intraband carrier cooling is significantly faster in quantum-dot solids. In addition we find that carriers diffuse from higher to lower energy sites in the quantum-dot solid within several picoseconds.
authors: Optoelectronic Material Section, Department of Chemical Engineering, Delft University of Technology, Julianalaan 136, 2628 BL, Delft, The Netherlands.
authors: Yunan
authors: Y
authors: Gao
authors: Elise
authors: E
authors: Talgorn
authors: Michiel
authors: M
authors: Aerts
authors: M Tuan
authors: MT
authors: Trinh
authors: Juleon M
authors: JM
authors: Schins
authors: Arjan J
authors: AJ
authors: Houtepen
authors: Laurens D A
authors: LD
authors: Siebbeles