Naphthalene-diimide-based all-conjugated block copolymer as an effective compatibilizer to improve the performance and thermal stability of all-polymer solar cells

Abstract

A new donor-acceptor type all-conjugated block copolymer (BCP), P(NDI-DBDT)-block-P(NDI-2T), is synthesized through the coupling of a naphthalene diimide (NDI)-bithiophene (2T) segment-based polymer (P1) and a NDI-dithenylbenzodithiophene (DBDT) segment-based polymer (P2)....

Improving Thermal and Photostability of Polymer Solar Cells by Robust Interface Engineering

“…In principle, the charge dissociation and collection probability ( P ) can be estimated from the J ph /J sat ratio under an external bias between the short‐circuit condition and the maximum power output condition. [ 21,60,61 ] Moreover, J sat will be only dominated by the maximum exciton generation rate ( G max ). Accordingly, G max will be equal to J sa t / qL , where q is the elementary charge and L is the thickness of the active layer.…”

“…According to our previous study, [ 21 ] this loss should stem from the thermal‐induced microphase separation in the BHJ layer (will be discussed soon), which results in deteriorated charge transport and dissociation. [ 21,61 ] The stability of unencapsulated devices under continuous LED illumination in an N 2 ‐controlled environment is also investigated and the results are presented in Figure 4b. Different to rapid decay of the control ZnO device, the NS‐GNS device exhibits a 10 times higher stability with a high T 80 lifetime of >2000 h. Similarly, the correlative of the corresponding photovoltaic parameters with the illumination aging time was plotted.…”

“…Notably, a common method used to date to predict the lifespan of the material is using the Arrhenius relationship. [ 21,61,72 ] It contributes to predict the lifetime from the extrapolation of accelerated aging data of failure time or degradation rates determined at elevated temperatures. In principle, Arrhenius extrapolations suppose that a chemical degradation process is governed by a degradation rate k d which is proportional to exp(− E a / k B T ), where E a is the activation energy of a failure condition, k B is the Boltzmann constant, and T is the temperature (K).…”

“…Details for the ITO glass cleaning process and device fabrication were as described previously. [ 61 ] The ZnO precursor solution was prepared by dissolving 0.1 g zinc acetate in 1 mL of 2‐methoxyethanol with 28 µL of ethanolamine. The ZnO layer was spin‐coated onto the ITO substrates and annealed at 200 °C for 1 hour in the air.…”

Polymer solar cells made with photocrosslinkable conjugated donor–acceptor block copolymers: improvement in the thermal stability and morphology with a single-component active layer

“…25–28 Moreover, various monomers for donor and acceptor blocks have been proposed and applied in CDABP synthesis. 29–33 However, it is challenging to verify whether all the blocks were introduced into the block copolymer. Because unreacted blocks are also macromolecular monomeric species, they are difficult to remove using a typical purification process, such as Soxhlet extraction.…”