%0 Journal Article %1 doi:10.1021/acsenergylett.7b00282 %A Barker, Alex J %A Sadhanala, Aditya %A Deschler, Felix %A Gandini, Marina %A Senanayak, Satyaprasad P %A Pearce, Phoebe M %A Mosconi, Edoardo %A Pearson, Andrew %A Wu, Yue %A Srimath Kandada, Ajay Ram %A Leitjens, Tomas %A De Angelis, Filippo %A Dutton, Siân E. %A Petrozza, Annamaria %A Friend, Richard H. %D 0 %J ACS Energy Letters %K defects light perovskite segragation soaking %N ja %P null %R 10.1021/acsenergylett.7b00282 %T Defect-Assisted Photoinduced Halide Segregation in Mixed-Halide Perovskite Thin Films %U http://dx.doi.org/10.1021/acsenergylett.7b00282 %V 0 %X Solution processable lead halide perovskites show immense promise for use in photovoltaics and other optoelectronic applications. The ability to tune their bandgap by alloying various halide anions (for example in CH3NH3Pb(I1-xBrx)3, 0<x<1) is however hampered by the reversible photoinduced formation of sub-bandgap emissive states. We find that ion segregation takes place via halide defects, resulting in iodide-rich low-bandgap regions close to the illuminated surface of the film. This segregation may be driven by the strong gradient in carrier generation rate through the thickness of these strongly absorbing materials. Once returned to the dark, entropically-driven intermixing of halides returns the system to a homogeneous condition. We present approaches to supress this process by controlling either the internal light distribution or the defect density within the film. These results are relevant to stability in both single- and mixed-halide perovskites, leading the way towards tuneable and stable perovskite thin films for photovoltaic and light-emitting applications.

@article{doi:10.1021/acsenergylett.7b00282, abstract = { Solution processable lead halide perovskites show immense promise for use in photovoltaics and other optoelectronic applications. The ability to tune their bandgap by alloying various halide anions (for example in CH3NH3Pb(I1-xBrx)3, 0<x<1) is however hampered by the reversible photoinduced formation of sub-bandgap emissive states. We find that ion segregation takes place via halide defects, resulting in iodide-rich low-bandgap regions close to the illuminated surface of the film. This segregation may be driven by the strong gradient in carrier generation rate through the thickness of these strongly absorbing materials. Once returned to the dark, entropically-driven intermixing of halides returns the system to a homogeneous condition. We present approaches to supress this process by controlling either the internal light distribution or the defect density within the film. These results are relevant to stability in both single- and mixed-halide perovskites, leading the way towards tuneable and stable perovskite thin films for photovoltaic and light-emitting applications. }, added-at = {2017-05-15T10:06:39.000+0200}, author = {Barker, Alex J and Sadhanala, Aditya and Deschler, Felix and Gandini, Marina and Senanayak, Satyaprasad P and Pearce, Phoebe M and Mosconi, Edoardo and Pearson, Andrew and Wu, Yue and Srimath Kandada, Ajay Ram and Leitjens, Tomas and De Angelis, Filippo and Dutton, Siân E. and Petrozza, Annamaria and Friend, Richard H.}, biburl = {https://www.bibsonomy.org/bibtex/2d1f9f0aac068f6bcd28a2f8120f93524/fabianopkm}, doi = {10.1021/acsenergylett.7b00282}, eprint = {http://dx.doi.org/10.1021/acsenergylett.7b00282}, interhash = {b1f5540e3c959bb0b43371b887963357}, intrahash = {d1f9f0aac068f6bcd28a2f8120f93524}, journal = {ACS Energy Letters}, keywords = {defects light perovskite segragation soaking}, number = {ja}, pages = {null}, timestamp = {2017-05-15T10:07:57.000+0200}, title = {Defect-Assisted Photoinduced Halide Segregation in Mixed-Halide Perovskite Thin Films}, url = {http://dx.doi.org/10.1021/acsenergylett.7b00282}, volume = 0, year = 0 }