Optical and ODMR spectroscopy of an induced triplet X-trap in 1,4-dibromobenzene single crystals

Optical detection of spin coherence in a defect center of a molecular crystal

“…We were able to show [6] that the defect consists of several DBB molecules lowered 27 cm-1 below the exciton band of DBB. At low temperatures only these molecules are populated and transport will only occur among energetically almost equivalent molecules, which will give rise to spin dephasing processes.…”

“…The characterization of the defect center by optical and cw ODMR specσ'Os copy will be reported in q띠te a det때 elsewhere [6]. 많 DBB defect center X D induced by DCB-d 4 is energetically 27 cm-1 below the DBB exciton band and shows two phosphorescence ori밍ns 2.3 cm-1 apart.…”

“…On both ori밍ns the same two sets of ODMR transitions are observed , that is altogether we find 6 ODMR 파les (set I: 3.006, 5.006 and 7.980 GHz; set II: 3.980, 5.215 and 9.213 GHz). Temperature variation shows [6] that excitation energy is transfered between these centers without promoting the excitation to the exciton band. We will restrict ourselves in this publication to spin coherence experiments performed on one of the ODMR transitions connecting the X and Z spin sublevels at 5.006 GHz of set I of the two ODMR transition frequency sets.…”

“…The decay time of the short component 자 is in the order of the HE decay time of about 7 f.LS. The decay time of the long component 까 corresponds to the short t더plet spin sublevellifetime (800 μs) [6] of the two mw connected sublevels. In prin며pIe one expects to observe both sublevel lifetimes of 800 μs and 2.7 ms [4], but SE intensity was not strong enou맹 to follow the signallonger than 1 ms.…”

“…We have 외ready applied some of the p띠se sequences to chemically mixed cryst외s [5][6][7] in order to get information about the extension and structure of induced defects in organic molecular crystals. These defects are induced by doping a molecular crystal with as compared to the host chemically different molecules.…”