%0 Journal Article %1 ADFM:ADFM201404421 %A Fang, Hong-Hua %A Raissa, Raissa %A Abdu-Aguye, Mustapha %A Adjokatse, Sampson %A Blake, Graeme R. %A Even, Jacky %A Loi, Maria Antonietta %D 2015 %J Advanced Functional Materials %K crystal perovskite photophysics single %N 16 %P 2378--2385 %R 10.1002/adfm.201404421 %T Photophysics of Organic–Inorganic Hybrid Lead Iodide Perovskite Single Crystals %U http://dx.doi.org/10.1002/adfm.201404421 %V 25 %X Hybrid organometal halide perovskites have been demonstrated to have outstanding performance as semiconductors for solar energy conversion. Further improvement of the efficiency and stability of these devices requires a deeper understanding of their intrinsic photophysical properties. Here, the structural and optical properties of high-quality single crystals of CH3NH3PbI3 from room temperature to 5 K are investigated. X-ray diffraction reveals an extremely sharp transition at 163 K from a twinned tetragonal I4/mcm phase to a low-temperature phase characterized by complex twinning and possible frozen disorder. Above the transition temperature, the photoluminescence is in agreement with a band-edge transition, explaining the outstanding performances of the solar cells. Whereas below the transition temperature, three different excitonic features arise, one of which is attributed to a free-exciton and the other two to bound excitons (BEs). The BEs are characterized by a decay dynamics of about 5 μs and by a saturation phenomenon at high power excitation. The long lifetime and the saturation effect make us attribute these low temperature features to bound triplet excitons. This results in a description of the room temperature recombination as being due to spontaneous band-to-band radiative transitions, whereas a diffusion-limited behavior is expected for the low-temperature range.

@article{ADFM:ADFM201404421, abstract = {Hybrid organometal halide perovskites have been demonstrated to have outstanding performance as semiconductors for solar energy conversion. Further improvement of the efficiency and stability of these devices requires a deeper understanding of their intrinsic photophysical properties. Here, the structural and optical properties of high-quality single crystals of CH3NH3PbI3 from room temperature to 5 K are investigated. X-ray diffraction reveals an extremely sharp transition at 163 K from a twinned tetragonal I4/mcm phase to a low-temperature phase characterized by complex twinning and possible frozen disorder. Above the transition temperature, the photoluminescence is in agreement with a band-edge transition, explaining the outstanding performances of the solar cells. Whereas below the transition temperature, three different excitonic features arise, one of which is attributed to a free-exciton and the other two to bound excitons (BEs). The BEs are characterized by a decay dynamics of about 5 μs and by a saturation phenomenon at high power excitation. The long lifetime and the saturation effect make us attribute these low temperature features to bound triplet excitons. This results in a description of the room temperature recombination as being due to spontaneous band-to-band radiative transitions, whereas a diffusion-limited behavior is expected for the low-temperature range.}, added-at = {2016-06-28T15:48:07.000+0200}, author = {Fang, Hong-Hua and Raissa, Raissa and Abdu-Aguye, Mustapha and Adjokatse, Sampson and Blake, Graeme R. and Even, Jacky and Loi, Maria Antonietta}, biburl = {https://www.bibsonomy.org/bibtex/2068eccc95bb266477b4d574be77f46ff/fabianopkm}, doi = {10.1002/adfm.201404421}, interhash = {660427d274bf6750c2448f8096fa1ba7}, intrahash = {068eccc95bb266477b4d574be77f46ff}, issn = {1616-3028}, journal = {Advanced Functional Materials}, keywords = {crystal perovskite photophysics single}, number = 16, pages = {2378--2385}, timestamp = {2016-06-28T15:48:07.000+0200}, title = {Photophysics of Organic–Inorganic Hybrid Lead Iodide Perovskite Single Crystals}, url = {http://dx.doi.org/10.1002/adfm.201404421}, volume = 25, year = 2015 }