Low-temperature recombination kinetics of photoexcited persistent charge carriers in conjugated polymer/fullerene composite films

Charge transfer in fullerene – porphyrin-derived dyads studied with light-induced electron spin resonance

“…The results presented in the figure and the shapes of the LESR signals confirm creation of the radicals, which are responsible for the LESR lines observed in our experiments. It is in reasonable agreement with the literature data for some organic chromophore-fullerene systems [34,44].…”

The localization of electrons in amorphous semiconductors: A twenty-first century perspective

“…It is clear that the model fits these data very well. Similar very accurate fits have been obtained for a-Ge:H [10] and an organic semiconductor [11]. The success of the model in these three materials shows first that the phenomenon is 'universal' as claimed and second that it is independent of the slopes of the densities of band-tail states.…”

“…Because the densities of band-tail states do not enter into the theory, it is applicable also to other tetrahedrally coordinated amorphous semiconductors. To date the major features of the model, including the 'universality', have been confirmed in a-Si:H [8], a-Ge:H [8,10] and an organic semiconductor consisting of a conjugated polymer and fullerine composite film [11].…”

Direct observation of UV-induced charge accumulation in inverted-type polymer solar cells with a TiOx layer: Microscopic elucidation of the light-soaking phenomenon

“…Organic solar-cell materials, such as polymers and fullerenes, have been studied by ESR. [20][21][22][23][24] However, the ESR study of organic solar cells has not yet been reported except for our studies. 18,19 Here we study the light-soaking phenomenon of IOSCs with a TiO x electron-collecting layer during device operation using ESR.…”

“…[9][10][11][12][13][14]16 To fully elucidate the light-soaking phenomenon, electron spin resonance (ESR) spectroscopy is the most suitable technique because ESR is a highly sensitive and nondestructive technique for directly observing the charges in organic semiconductors and their devices at the molecular level. [17][18][19][20][21][22][23][24] ESR studies have demonstrated a clear correlation between performance deterioration and charge accumulation (or trappings) in a normal-type OSC, 18 and have clarified degradation mechanism due to charge formation during device fabrication. 19 As noted above, the light-soaking phenomenon has been considered to be related to charge trappings.…”