All-PSCs Based on Large Bandgap 2-2.5 eV Donor Polymers

1 All-PSCs Based on Large Bandgap (2-2.5 eV) Donor Polymers 

In the blend of two polymers, the one with lower energy levels tends to accept electrons and thus can function as an acceptor. Besides the observed exci-ton dissociation and photoluminescence quenching, both groups (Friend and Heeger) reported dramatically enhanced external quantum efficiency of the blend-based cells over the pure polymer-based cells. Although the power conversion efficiencies (PCE) of these early all-PSCs were low ( 1%), this revolutionary work opened the interesting and important development of all-PSCs in the past 20 years. 

Mini-Summary (Section 4.2.2). To summarize the overall research efforts in polythiophene-based all-PSCs, there are several key factors that need to be considered in order to improve the performance of all-PSCs beyond that achievable for polythiophene-based all-PSCs. 

With these arguments, it is important to develop all-PSCs based on lower bandgap donor polymers that have lower-lying LUMO levels than 

In all three cases of the all-PSCs above, the LUMO offsets between the donor and acceptor polymers were smaller than in P3HT N2200-based all-PSCs. The value of LUMO offset is one of the most important parameters 

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