perovskite and lead-chloride

Topics: Calcium Compounds; Catalysis; Catechols; Gas Chromatography-Mass Spectrometry; Lead; Lignin; Oxides; Phenol; Propylamines; Temperature; Thermodynamics; Titanium; Ultraviolet Rays

The presence of the PbI

Topics: Calcium Compounds; Electronics; Gold; Lead; Lighting; Microscopy, Scanning Tunneling; Optical Imaging; Oxides; Solar Energy; Surface Properties; Titanium

Developments in organic-inorganic lead halide-based perovskite solar cells have been meteoric over the last 2 years, with small-area efficiencies surpassing 15%. We address the fundamental issue of how these cells work by applying a scanning electron microscopy-based technique to cell cross-sections. By mapping the variation in efficiency of charge separation and collection in the cross-sections, we show the presence of two prime high efficiency locations, one at/near the absorber/hole-blocking-layer, and the second at/near the absorber/electron-blocking-layer interfaces, with the former more pronounced. This 'twin-peaks' profile is characteristic of a p-i-n solar cell, with a layer of low-doped, high electronic quality semiconductor, between a p- and an n-layer. If the electron blocker is replaced by a gold contact, only a heterojunction at the absorber/hole-blocking interface remains.

Topics: Calcium Compounds; Chlorides; Coordination Complexes; Electric Power Supplies; Lead; Microscopy, Atomic Force; Microscopy, Electron, Scanning; Oxides; Semiconductors; Solar Energy; Titanium