Single molecule detection and photobleaching study of a phosphorescent dye: organometallic iridium(III) complex

Ratiometric Single‐Nanoparticle Oxygen Sensors for Biological Imaging

“…Single-molecule detection of triplet emission in transition-metal complexes represents a challenging task because of the typically low phosphorescence quantum yields and very low radiative rates. [31][32][33] The PtOEP-doped CPdots are expected to present substantially brighter phosphorescence than that of single phosphorescent molecules because of the large number of phosphorescent chromophores per particle (ca. 700 phosphorescent chromophores in a particle of ca.…”

Effect of ligands in two-photon excited luminescence of organometallic iridium complexes

“…Its emission spectrum is dominated by a phosphorescence band centered around 510 nm due to a triplet metal-to-ligand charge transfer state ( 3 MLCT). The high emission quantum yield and short luminescence lifetime enabled the study of several phosphorescent organometallic complexes on a single-molecule level [2][3][4][5]. Recently, we used a timeresolved technique to measure the excited-state lifetime of Ir(ppy) 3 molecules on ensemble and single-molecule level [6].…”

“…Many complexes of iridium, ruthenium, or platinum are characterized by high-phosphorescence quantum efficiency and relatively short triplet-state lifetimes (ms to tens of ms on average). One of the most studied iridium complexes, fac-tris(2-phenylpyridine) iridium (Ir(ppy) 3 ), has a quantum efficiency of up to 0.92 and a lifetime of 1.2 ms in a polystyrene matrix [1]. Its emission spectrum is dominated by a phosphorescence band centered around 510 nm due to a triplet metal-to-ligand charge transfer state ( 3 MLCT).…”

“…However, to this point the origin of the two-photon excited luminescence remains unclear. In this work we use an iridium complex similar to Ir(ppy) 3 , with the exception that one of the phenylpyridine ligands is modified with an aldehyde group. The resulting compound, bis(2-phenylpyridyl)-2-(4-formylphenyl)-pyridyl iridium (Ir(ppy) 2 fppy), has lower symmetry and a red-shifted tripled emission energy due to localization of the excitation on the modified ligand.…”

Single‐Molecule Electroluminescence of a Phosphorescent Organometallic Complex

“…[12][13][14][15] The heavy metals in organometallic complexes cause shortening of the triplet excitedstate lifetime to a few microseconds and an increase in the phosphorescence quantum efficiency, [16] enabling the PL study of several organometallic complexes at the single-molecule level. [17][18][19][20] The EL process on the level of a single dopant entity has been observed for colloidal quantum dots, [21,22] silver clusters [23] and carbon nanotubes.[24] Also, electric-field-induced chemiluminescence in single conjugated polymer nanoparticles has been reported recently.[25] Herein, we have succeeded in detecting the EL signal from single molecules of an organic dye doped at a very low concentration in a non-conjugated polymer host matrix. The single-molecule EL detection was possible because 1) charge recombination in the host is localized in distinct sites, 2) the onset voltage for EL of the dopant molecules is lower than that for the host and 3) the dopant molecules could be separated from the host EL background spectrally.…”