Synthetic Control of the Photoluminescence Stability of Organolead Halide Perovskites

Freppon, Daniel J.; Men, Long; Bhattacharjee, Ujjal; Rosales, Bryan A.; Zhu, Feng; Petrich, Jacob W.; Smith, Emily A.; Vela, Javier

doi:10.29356/jmcs.v63i3.623

Cited by 1 publication

(3 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This change in relaxation time supports the suggestion that the addition of organic precursors (and hence, the conditions under which synthesis takes place) strongly affects the crystal quality, which, in turn, governs the ligand-migration time. The dynamic behavior of the PL peak in the presence of excess precursor is also manifested in a steady-state laser–assisted PL peak shift . In addition to the shift in the predominant band-edge peak, a higher-energy peak at ∼620 nm appears.…”

Section: Results Anddiscussionmentioning

confidence: 96%

“…The dynamic behavior of the PL peak in the presence of excess precursor is also manifested in a steady-state laser−assisted PL peak shift. 58 In addition to the shift in the predominant band-edge peak, a higher-energy peak at ∼620 nm appears. This higher-energy peak is also apparent in a freshly prepared perovskite solution but disappears as the sample ages.…”

Section: ■ Introductionmentioning

confidence: 99%

“…A red-shift of the PL peak of low-dimensional CH 3 NH 3 PbI 3 accompanying sample aging, after preparation, has been observed and discussed. 58 Red-shifted PL arises from annealing, which occurs via SSP formation, and is associated with cation migration.…”

Section: ■ Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Nanosecond, Time-Resolved Shift of the Photoluminescence Spectra of Organic, Lead-Halide Perovskites Reveals Structural Features Resulting from Excess Organic Ammonium Halide

et al. 2019

Self Cite

View full text Add to dashboard Cite

The effort to drive solution-based perovskite solar cells towards higher efficiency has been considerable, reaching over 24%. Such progress has been made possible by the low-energy barrier to crystallization. The low-energy barrier in the reverse direction, however, also renders them susceptible to dissociation from heat, moisture, and photoexcitation. Consequently, studies that provide information on the stability of perovskites are of considerable importance. It has been reported that perovskite crystals formed using different stoichiometries of the organic precursors and metal halide are equivalent. Our findings, however, suggest that the difference in reaction pathways affects the quality of the final crystal and that changes in morphology and the production of any defects can lead to differences in behavior under illumination. Here, we present photoluminescence spectra subsequent to nanosecond photoexcitation of perovskites synthesized under various conditions. Our results indicate that the presence of excess precursors (i.e., CH3NH3X, X= I and surfactant) gives rise to an ~20-nanosecond relaxation time with which the photoluminescence spectrum achieves its equilibrium value. This relaxation is absent in bulk, polycrystalline material. This is, to our knowledge, the first report of the ~20-ns relaxation time, which we attribute to cation migration. These structural changes are not detectable subsequent to photoexcitation by x-ray diffraction, nor are they detectable by in situ x-ray diffraction during photoexcitation. Disciplines DisciplinesMaterials Chemistry | Physical Chemistry Comments Comments ABSTRACTThe effort to drive solution-based perovskite solar cells towards higher efficiency has been considerable, reaching over 24%. Such progress has been made possible by the low-energy barrier to crystallization. The low-energy barrier in the reverse direction, however, also renders them susceptible to dissociation from heat, moisture, and photoexcitation. Consequently, studies that provide information on the stability of perovskites are of considerable importance. It has been reported that perovskite crystals formed using different stoichiometries of the organic precursors and metal halide are equivalent. Our findings, however, suggest that the difference in reaction pathways affects the quality of the final crystal and that changes in morphology and the production of any defects can lead to differences in behavior under illumination. Here, we present photoluminescence spectra subsequent to nanosecond photoexcitation of perovskites synthesized under various conditions. Our results indicate that the presence of excess precursors (i.e., CH3NH3X, X= I and surfactant) gives rise to an ~20-nanosecond relaxation time with which the photoluminescence spectrum achieves its equilibrium value. This relaxation is absent in bulk, polycrystalline material. This is, to our knowledge, the first report of the ~20-ns relaxation time, which we attribute to cation migration. These structural changes are not detectable subsequen...

show abstract

Section: Results Anddiscussionmentioning

confidence: 96%

Section: ■ Introductionmentioning

confidence: 99%