The effect of thermal annealing on defect states, light intensity and photocurrent of organic solar cells

Prominent processing techniques to manipulate semiconducting polymer microstructures

“…Instead, melt annealing is used when a certain polymeric system is heated above its melting point. 282 Some of these microstructures were recently further employed either to enhance the efficiency of OPVs, 274,277,283 OFETs, 275,278 organic resistors, 280 and other devices, 273 or, for instance, to simply boost the cytocompatibility of natural rubber 276 or electrical conductivity of non-conjugated polymers. 279 A precise control over the thermal history of thin films of crystalline BCPs such as P2VP-b-PEO (see its chemical structure in the inset of Fig.…”

“…283 The latter was further shown to significantly increase when using active films of P3HT:PCBM in which the crystallinity, domain size and purity, molecular p-p stacking, chain orientation and vertical phase separation were optimized by thermal annealing. 274 For more interesting examples based on thermal annealing, the readers should refer to other relevant and comprehensive works reported in the literature. 277,279 Towards the end of this section, it is necessary to further exemplify the importance of melt-annealing with respect to thermal annealing.…”

“…Various heating/cooling protocols involving melting (T m ) and crystallization (T c ) temperatures [269][270][271][272] were established in time and proved to be efficient in delivering a plethora of ordered polymer microstructures. [269][270][271][272][273][274][275][276][277][278][279][280][281] Here, one refers to thermal annealing, when a polymeric system is annealed above the T c . Instead, melt annealing is used when a certain polymeric system is heated above its melting point.…”

“…Some of these microstructures were recently further employed either to enhance the efficiency of OPVs, 274,277,283 OFETs, 275,278 organic resistors, 280 and other devices, 273 or, for instance, to simply boost the cytocompatibility of natural rubber 276 or electrical conductivity of non-conjugated polymers. 279…”

Competing Influences of Cooling Rate and Diluent Concentration on Crystallization of Poly(3-hexylthiophene)

“…Crystallization of P3HT from the molten state has also been of interest to many researchers. The role of characteristic properties of the polymer such as molecular weight, polydispersity, and regioregularity were evaluated with respect to structure formation and the resulting crystallinity of P3HT. − To enhance the degree of order when P3HT is crystallized from the molten state, different thermal protocols were employed. − Several postpreparation processes such as high-temperature rubbing, solvent vapor, and thermal annealing − were employed to reduce the number density of defects in the crystalline structure.…”