N-type polymer containing non-condensed ring receptor unit as well as preparation method and application of n-type polymer

Abstract

The invention discloses an n-type polymer containing a non-condensed ring receptor unit as well as a preparation method and application of the n-type polymer. The structural formula of the n-type polymer based on the non-condensed ring receptor unit is shown as a formula I, a copolymerization unit 1 is an A2-D-A1-D-A2 type non-condensed ring unit, A1 and A2 are electron deficiency units, and D isan electron supply unit; and a copolymerization unit 2 is a conjugated aromatic ring unit, and the number n of the repetitive units is a natural number of 1-10000. The polymer provided by the invention is relatively low in synthesis cost, all intermediates are simple in synthesis method and easy to purify, and the obtained polymer shows a wide absorption range and a high light absorption coefficient, can realize better optical absorption complementation and energy level matching with a p-type semiconductor material, and is applied to organic solar cells. The device has good photoelectric response performance.

Description

technical field [0001] The invention belongs to the technical field of photoelectric materials and applications, and specifically relates to a class of n-type polymers containing non-condensed ring acceptor units and their preparation methods and applications. Background technique [0002] In recent years, polymer solar cells (PSCs) have developed rapidly, among which all-polymer solar cells (all-PSCs) using p-type polymers as donors and n-type polymers as acceptors Due to the advantages of tuned complementary absorption, good film stability, and excellent mechanical properties, more and more attention has been paid to it. However, due to the lack of high-efficiency polymer donors / acceptors, and the long-term problems of the microscopic phase separation structure of the photovoltaic active layer and the unsatisfactory charge mobility, its development is relatively slow, and its energy conversion efficiency lags behind that of small molecule materials. Somatic PSCs. [0003...

AI Technical Summary

Problems solved by technology

However, due to the lack of high-efficiency polymer donors / acceptors, and the long-term problems of the microscopic phase separation structure of the photovoltaic active layer and the unsatisfactory charge mobility, its development is relatively slow, and its energy conversion efficiency lags behind that of small molecule materials. Somatic PSCs

[0003] At present, most n-type polymer acceptor materials are based on imide units, among which N2200 is one of the most concerned acceptor materials, but it has obvious defects: low absorption coefficient (thin film absorbs light at 700nm The coefficient is only 0.3*10 5 cm -1 ), which greatly limits the short-circuit current (J sc ) will eventually affect device performance

[0005] However, the synthesis cost of such fused-ring non-fullerene acceptor units is relatively high, which is not conducive to large-scale commercial production

Through research literature, it is found that some small-molecule non-fullerene acceptors based on non-condensed ring structures exhibit high light absorption coefficient and good device performance, and their synthesis steps are relatively short and the synthesis cost is relatively low. The introduction of non-fused ring acceptor units as conjugated backbones into n-type polymers has not been reported

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