CH3NH3PbI3 from non-iodide lead salts for perovskite solar cells via the formation of PbI2.

We report the formation of CH3NH3PbI3 from more soluble, non-iodide lead salts like Pb(SCN)2 and Pb(NO3)2. When exposed to CH3NH3I vapours, the colourless lead salts turned yellow before the formation of the black perovskite. Investigation of this yellow intermediate suggests that anion exchange (converting lead salts to PbI2) precedes the perovskite formation.

Reducing optical losses in organic solar cells using microlens arrays: theoretical and experimental investigation of microlens dimensions.

The performance of organic photovoltaic devices is improving steadily and efficiencies have now exceeded 10%. However, the incident solar spectrum still largely remains poorly absorbed. To reduce optical losses, we employed a microlens array (MLA) layer on the side of the glass substrate facing the incident light; this approach does not interfere with the processing of the active-layer.

Microlens array induced light absorption enhancement in polymer solar cells.

Over the last decade, polymer solar cells (PSCs) have attracted a lot of attention and highest power conversion efficiencies (PCE) are now close to 10%. Here we employ an optical structure - the microlens array (MLA) - to increase light absorption inside the active layer, and PCE of PSCs increased even for optimized devices. Normal incident light rays are refracted at the MLA and travel longer optical paths inside the active layers.