Perovskite solar cell defects trap charge carriers and then release them again

Among the astir breathtaking materials for star cells are the alleged MAPI semiconductors. They dwell of integrated methylammonium cations and pb iodide octahedra that signifier a perovskite structure. MAPI based star cells person achieved efficiencies of 25% wrong a fewer years. But truthful far, the semi-organic semiconductors are inactive aging rapidly.

Now, for the archetypal time, an HZB squad led by Dr. Artem Musiienko has precisely characterized 5 antithetic defect types and measured the enactment betwixt these defects and the complaint carriers.

Using a operation of highly delicate spectroscopy methods, they succeeded successful experimentally determining the concentration, energy, seizure cross-section and complaint seizure clip of the antithetic defects and creating a representation of the defects. By utilizing electrical pulses, they made definite that the measurements did not impact the prime of the material.

The measurement results let the reliable differentiation betwixt electron and spread transport and the determination of their astir important parameters: Mobilities, lifetimes and diffusion lengths. "This enactment frankincense provides answers to questions that person been discussed for a agelong clip successful the tract of perovskite solar cells," says Musiienko.

An important finding: a ample proportionality of the defects merchandise the captured charge carriers again aft a abbreviated time. "This whitethorn partially explicate these peculiarly precocious efficiencies of the MAPI perovskites," says Musiienko.  These results pave the mode to optimize MAPI perovskites successful presumption of defect concentration, combining precocious efficiencies with bully stability.

The probe was published successful Advanced Functional Materials.

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