Repair of defects in photoactive layer of organic solar cells

Green and stable processing of organic light-emitting diodes from aqueous nanodispersions

“…An active layer containing cracks and holes leads to undesired current pathways between the cathode and anode, resulting in a high leakage current and short-circuits. 31,32 Furthermore, it should be realized that due to the finite size of the particles, the exact thickness of the active layer may be difficult to control. Hence, prior to fabricating the devices, we investigate film formation during casting, this time using PEDOT:PSS-anode-glass substrates to also study the possible influence of the anode material.…”

On the short circuit resilience of organic solar cells: prediction and validation

“…associated with charge carrier recombination as well as microscopic current pathways, 6 perhaps as a consequence of roughness-related issues. 7,13 The latter is probably also responsible for the relatively low series resistance R s . Besides the values of the effective resistance elements, Table 1 also contains the open circuit voltage (V oc ), short circuit current density (J sc ) 12 , fill factor (FF), and light-to-power conversion efficiency (η) of the OSCs.…”

“…7 In order to make a comparison with the predictive calculations given above, we plot the resistance measured across the PEDOT:PSS-LiF/Al junctions (denoted R j ) as a function of voltage in Figure 3b. The size of these junctions compares well with macroscopic photoactive layer defects expected to result from handling damage or dewetting, and deliberately implemented in OSC devices during our previous investigations.…”

“…Unfortunately, the production yield of such thin-film devices is still suppressed by the occurrence of short circuits associated with processing imperfections and handling damage. 6,7 As a result of this treatment the PEDOT:PSS becomes locally over-oxidized and loses its conducting properties in regions where it is exposed. typically <100 nm) that are printed or coated on top of each other.…”

“…typically <100 nm) that are printed or coated on top of each other. 7 Hence, integration of this repair method in an automated production environment would require a dedicated detection system capable of localizing defects in order to subsequently dispense oxidizing solution in a spatially controlled fashion. 6,7 As a result of this treatment the PEDOT:PSS becomes locally over-oxidized and loses its conducting properties in regions where it is exposed.…”