Dimethylammonium Incorporation in Lead Acetate Based MAPbI Perovskite Solar Cells.

Over the last years, several different pathways have been suggested for producing perovskite thin films for solar cell applications. While the merit of these methods with respect to the solar cell efficiency have been shown, the actual composition of the resulting thin films is often not investigated. Here, we show that methylammonium lead iodide films produced using lead acetate as a lead source can have up to 15 % dimethylammonium incorporated into their crystal structure, even though this ion is often consider to be too large for incorporation.

The effect of oxygen on the efficiency of planar p-i-n metal halide perovskite solar cells with a PEDOT:PSS hole transport layer.

Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is frequently used as hole transport layer in planar p-i-n perovskite solar cells. Here we show that processing of a metal halide perovskite layer on top of PEDOT:PSS spin coating of a precursor solution chemically reduces the oxidation state of PEDOT:PSS. This reduction leads to a lowering of the work function of the PEDOT:PSS and the perovskite layer on top of it.

The Importance of Moisture in Hybrid Lead Halide Perovskite Thin Film Fabrication.

Moisture, in the form of ambient humidity, has a significant impact on methylammonium lead halide perovskite films. In particular, due to the hygroscopic nature of the methylammonium component, moisture plays a significant role during film formation. This issue has so far not been well understood and neither has the impact of moisture on the physical properties of resultant films.