title: Photovoltaic effect in individual asymmetrically contacted lead sulfide nanosheets.
abstract: Solution-processable, two-dimensional semiconductors are promising optoelectronic materials which could find application in low-cost solar cells. Lead sulfide nanocrystals raised attention since the effective band gap can be adapted over a wide range by electronic confinement and observed multi-exciton generation promises higher efficiencies. We report on the influence of the contact metal work function on the properties of transistors based on individual two-dimensional lead sulfide nanosheets. Using palladium we observed mobilities of up to 31 cm(2) V(-1) s(-1). Furthermore, we demonstrate that asymmetrically contacted nanosheets show photovoltaic effect and that the nanosheets' height has a decisive impact on the device performance. Nanosheets with a thickness of 5.4 nm contacted with platinum and titanium show a power conversion efficiency of up to 0.94% (EQE 75.70%). The results underline the high hopes put on such materials.
authors: Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany. klinke@chemie.uni-hamburg.de.
authors: Sedat
authors: S
authors: Dogan
authors: Thomas
authors: T
authors: Bielewicz
authors: Vera
authors: V
authors: Lebedeva
authors: Christian
authors: C
authors: Klinke