Energy conversion efficiency

Computer science

Gene

Optics

Perovskite (structure)

Recombination

Photoluminescence

Optoelectronics

Biochemistry

Computer graphics (images)

Perovskite solar cell

Crystallography

Planar

Chemistry

Materials science

Spontaneous emission

Physics

Laser

Nature Energy

The performance of perovskite solar cells is predominantly limited by non-radiative recombination, either through trap-assisted recombination in the absorber layer or via minority carrier recombination at the perovskite/transport layer interfaces. Here, we use transient and absolute photoluminescence imaging to visualize all non-radiative recombination pathways in planar pin-type perovskite solar cells with undoped organic charge transport layers. We find significant quasi-Fermi-level splitting losses (135 meV) in the perovskite bulk, whereas interfacial recombination results in an additional free energy loss of 80 meV at each individual interface, which limits the open-circuit voltage (VOC) of the complete cell to ~1.12 V. Inserting ultrathin interlayers between the perovskite and transport layers leads to a substantial reduction of these interfacial losses at both the p and n contacts. Using this knowledge and approach, we demonstrate reproducible dopant-free 1 cm2 perovskite solar cells surpassing 20% effi...

Visualization and suppression of interfacial recombination for high-efficiency large-area pin perovskite solar cells