Design,Synthesis And Application Study Of Naphthalocyanine-derivatives For N-type Organic Semiconductor Materials

Naphthalocyanine（Nc）derivatives with large-conjugated cores are excellent organic hole transporting materials,which have high molar extinction coefficients and good stability.However,they have poor solubility,and their lowest unoccupied molecular orbital（LUMO）energy levels are too high to be electron transporting materials.In this work,the electron-withdrawing imide groups with long alkyl chains were introduced into the phthalocyanines to increase the solubility and reduce LUMO energy levels.A series of novel naphthalocyanine tetraimides were designed,synthesized,and applied to bulk-heterojunction organic solar cells（BHJOSCs）as electron-transporting materials.It contains the following two sections.1)Design,sysnthesis and photovoltaic application study of gallium naphthalocyanine tetraimides（compounds 9-13）as active layer acceptors.In this study,five gallium naphthalocyanine tetraimides with 6-undecyl alkyl chain and different axial substituent groups were synthesized from o-xylene through eleven-step reaction,including bromination,photocatalytic bromination,Diels-Alder,hydrolysis,dehydration,imide alkylation,and substitution.These compounds have good solubility（solubility in chloroform>30 mg/m L）,low LUMO energy levels（-3.89～-3.95 e V）,wide film absorption range（600-1200 nm）,high molar extinction coefficient(3.75～6.18×10⁵ M^-1 cm^-1),and good thermal stability（T_d>325 ℃）.They could be used as acceptors in bulk-heterojunction solar cells（BHJOSCs）.The power conversion efficiency of compound 12 was 1.28%.2)Design,synthesis and photovoltaic applications study of silicon naphthalocyanine tetraimides as cathode interface layer materials.In this study,two silicon naphthalocyanine tetraimides with semi-perfluoroalkyl chains and two different dimethylamines were synthesized from 6,7-dibromonaphthalic anhydride through six-step reaction,including semi-perfluorinated alkylation of imides,cyanide substitution,condensation,and coordination.Both of them have wide film absorption range（600-1100 nm）,high molar extinction coefficients(6.08～6.12×10⁵M^-1 cm^-1),good thermal stability（T_d>185 ℃）,low LUMO energy level（-3.92～-3.93 e V）,and moderate solubility（solubility in methanol>1 mg/m L）.compound 19 was used as cathode interface layer materials in PM6/Y6-based BHJOSCs.Comparing with the BHJOSCs without cathode interface layers,the power conversion efficiency was increased from12.00%to 15.27%.This is the first time for naphthalocyanine tetraimides to be used as cathode interface layer materials in solar cells.