0000000000559667
AUTHOR
Ellen Moons
Intrinsic Organic Semiconductors as Hole Transport Layers in p–i–n Perovskite Solar Cells
Thin polymeric and small-molecular-weight organic semiconductors are widely employed as hole transport layers (HTLs) in perovskite solar cells. To ensure ohmic contact with the electrodes, the use of doping or additional high work function (WF) interlayer is common. In some cases, however, intrinsic organic semiconductors can be used without any additive or buffer layers, although their thickness must be tuned to ensure selective and ohmic hole transport. Herein, the characteristics of thin HTLs in vacuum-deposited perovskite solar cells are studied, and it is found that only very thin (<5 nm) HTLs readily result inhigh-performing devices, as the HTL acts as a WF enhancer while still ens…
Efficient Wide-Bandgap Mixed-Cation and Mixed-Halide Perovskite Solar Cells by Vacuum Deposition
Vacuum deposition methods are increasingly applied to the preparation of perovskite films and devices, in view of the possibility to prepare multilayer structures at low temperature. Vacuum-deposited, wide-bandgap solar cells based on mixed-cation and mixed-anion perovskites have been scarcely reported, due to the challenges associated with the multiple-source processing of perovskite thin films. In this work, we describe a four-source vacuum deposition process to prepare wide-bandgap perovskites of the type FA1-n Cs n Pb(I1-x Br x )3 with a tunable bandgap and controlled morphology, using FAI, CsI, PbI2, and PbBr2 as the precursors. The simultaneous sublimation of PbI2 and PbBr2 allows the…