Unraveling the Room-Temperature Spin Dynamics of Photoexcited Pentacene in Its Lowest Triplet State at Zero Field

2019 ◽  
Vol 123 (39) ◽  
pp. 24275-24279 ◽  
Author(s):  
Hao Wu ◽  
Wern Ng ◽  
Shamil Mirkhanov ◽  
Arman Amirzhan ◽  
Supamas Nitnara ◽  
...  
Keyword(s):  
Triplet State ◽  
Room Temperature ◽  
Spin Dynamics ◽  
Zero Field

Photoluminescence Processes in the Triplet State of Phosphorescent Organic Materials: Ir(ppy)3 Doped in TPD

2006 ◽  
Vol 517 ◽  
pp. 173-182
Author(s):  
Nadeer Aljaroudi ◽  
Taiju Tsuboi
Keyword(s):  
Triplet State ◽  
Room Temperature ◽  
Theoretical Calculations ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Energy Diffusion ◽  
Temperature Dependences ◽  
Level Model ◽  
Pl Intensity ◽  
Good Agreement

Photoluminescence (PL) measurements have been made for a spin-coated thin film of phosphorescent tris(2-phenylpyridine) iridium [Ir(ppy)3] doped in N,N’-bis (3-methylphenyl)-N, N’-bis(phenyl)-benzidine (TPD) host material in the temperature range from 10 K to room temperature. When temperature is increased from 10 K to 300 K, the PL intensity of Ir(ppy)3 increases from 10 K and decreases above about 200 K. Theoretical calculations are undertaken for the temperature dependence using (1) a three-level model where three zero-field splitting substates are generated in the triplet state of Ir(ppy)3 and (2) endothermic energy transfer from the TPD host to the Ir(ppy)3 guest, and (3) energy diffusion from the excited TPD to the neighboring unexcited TPD. A good agreement was obtained between the measured and calculated temperature dependences of the PL intensity.

Zero-field magnetic resonance of the photo-excited triplet state of pentacene at room temperature

2000 ◽  
Vol 113 (24) ◽  
pp. 11194-11201 ◽  
Author(s):  
Tran-Chin Yang ◽  
David J. Sloop ◽  
S. I. Weissman ◽  
Tien-Sung Lin
Keyword(s):  
Magnetic Resonance ◽  
Triplet State ◽  
Room Temperature ◽  
Excited Triplet State ◽  
Zero Field ◽  
Excited Triplet

Room temperature phosphorimetric determination of cyanide based on triplet state energy transfer

2003 ◽  
Vol 491 (1) ◽  
pp. 27-35 ◽  
Author(s):  
Marı́a Teresa Fernández-Argüelles ◽  
José M Costa-Fernández ◽  
Rosario Pereiro ◽  
Alfredo Sanz-Medel
Keyword(s):  
Energy Transfer ◽  
Triplet State ◽  
Room Temperature ◽  
State Energy ◽  
Triplet State Energy

The EPR Zero-Field Splitting D and its Pressure and Temperature Dependence for Trigonal Mn2+ Centers in [Zn(H2O)6](BF4)2:Mn2+ Crystal

2006 ◽  
Vol 61 (5-6) ◽  
pp. 289-292 ◽  
Author(s):  
Hong-Gang Liu ◽  
Xiao-Xuan Wu ◽  
Wen-Chen Zheng ◽  
Lv He
Keyword(s):  
Temperature Dependence ◽  
Room Temperature ◽  
Coupling Mechanism ◽  
Zero Field ◽  
Spin Orbit Coupling ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
Thermal Expansion Coefficients ◽  
Perturbation Formula ◽  
Expansion Coefficients

The EPR zero-field splitting D (= b02 ) and its pressure and temperature dependence for trigonal Mn2+ centers in low and room temperature phases in [Zn(H2O)6](BF4)2 :Mn2+ crystal are studied by a high-order perturbation formula based on the dominant spin-orbit coupling mechanism. From the studies, the local trigonal distortion angles, the local angular compressibilities and the local angular thermal expansion coefficients for Mn2+ centers in both phases of the [Zn(H2O)6](BF4)2 crystal are estimated. The results are discussed

ESR Triplet Exciton Spectrum of Acridine Orange

1971 ◽  
Vol 26 (4) ◽  
pp. 763-768 ◽  
Author(s):  
Hartmut Schmidt
Keyword(s):  
Triplet State ◽  
Acridine Orange ◽  
Exciton State ◽  
Triplet Exciton ◽  
Zero Field ◽  
Strong Temperature Dependence ◽  
Zero Field Splitting ◽  
Temperature Spectrum ◽  
Water Matrix ◽  
Exciton Spectrum

Abstract The triplet state of acridine orange dissolved in methanol/water matrix was investigated by ESR. In absence of oxygen a strong temperature dependence of the spectra was observed. At low temper­ature (100 °K) the zero-field splitting parameters calculated from the triplet spectrum are: X/hc = 0.0050 cm-1, Y/hc= 0.0342 cm-1, Z/hc=0.0387 cm-1 , at higher temperature (140 °K) : X*(hc=0.0056 cm-1, Y*/hc=0.0206 cm-1, Z*/hc = 0.0262 cm-1 . It was assumed that the low temperature spectrum is caused by isolated molecules in the triplet state while the high temperature spectrum must be attributed to the triplet exciton state of the acridine orange dimer. From the theory of the ESR triplet exciton spectra it can be shown that in the dimer state of acridine orange the molecular planes form an angle of 50° or 130°. However, it cannot be excluded that the dimer configuration differs in the ground or excited singlet state from the triplet state.

Transient electron paramagnetic resonance of the triplet state of P700 in photosystem I: Evidence for triplet delocalization at room temperature

Biochemistry ◽  
1993 ◽  
Vol 32 (18) ◽  
pp. 4842-4847 ◽  
Author(s):  
Ina Sieckmann ◽  
Klaus Brettel ◽  
Christian Bock ◽  
Arthur van der Est ◽  
Dietmar Stehlik
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Triplet State ◽  
Photosystem I ◽  
Room Temperature ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic

Photophysics of the lowest triplet state in 2-benzoylpyridine crystals. II. Optically detected e. p. r. in zero and high magnetic fields

1979 ◽  
Vol 369 (1737) ◽  
pp. 187-206 ◽  
Keyword(s):  
Triplet State ◽  
Rate Constants ◽  
Radiative Decay ◽  
Dynamic Properties ◽  
Deep Trap ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Zero Field ◽  
Spin Lattice ◽  
Optically Detected

Optically detected zero-field resonance has been used to characterize the intrinsic and deep trap 3 nπ * states in single crystals of 2-benzoylpyridine at 4.2 K. The dynamic properties of these states were studied by means of time-resolved modulated phosphorescence (t. r. m. p.) and estimates for the rate constants for depopulation and spin-lattice relaxation of the magnetic sub-levels obtained by computer simulation. For all species, depopulation from ז z dominates, having rates of order 100 s -1 , but the ז x and ז y sub-states have substantial radiative activity. The orientations of the fine-structure tensors of the magnetic species were determined from high-field e. p. r. spectra. Assuming that z is parallel to C = O, excitation causes the C = O direction to change by 8 ± 2° for the intrinsic species and by an in-significant amount for the deep trap. These spectra also demonstrated that the intrinsic triplet state is mobile. This species is believed to be a polaron with slow intersite hopping rate. A maximum energy transfer rate of 10 4 -10 5 s -1 was found for transfer between translationally inequivalent sites symmetry-related by twofold rotation about the crystal b -axis. Rate estimates for transfer to the other two translationally inequivalent sites established the two dimensional nature of the polaron. The sign and shape of the zero-field resonances for the intrinsic species were found to depend on whether excitation was through S 1 or T 1 . From the parameters required to simulate the corresponding t. r. m. p. signals it is inferred that the changes are largely due to differences in the rate constants for non-radiative decay. The deep trap was shown to have an orientation and magnetic properties similar to those of the intrinsic species, and is believed to be a physical defect. It has radiative activity from the ז x sub-level which is significantly less than for the intrinsic species. Spin-lattice relaxation is fast for the mobile intrinsic species ( ca . 10 4 s -1 ) compared with the deep trap rate ( ca . 50 4 s -1 ). For the intrinsic species a field dependence for spin-lattice relaxation is apparent.

Sign in / Sign up

Export Citation Format

Share Document