Solution-Processed Non-Fullerene-based Organic Photodiodes For Narrowband Red Light Detection

Organic photodetectors have attracted the attention of researchers again because of the rapid development of non-fullerene materials.The ultimate goal of this thesis is to realize the narrow spectral response of non-fullerene-based organic photodetectors in red region and to explore its potential in color imaging.In this thesis,first,DIBSQ and SBDTIC with overlapped absorption were mixed to obtain a narrow absorption spectrum in red region,which has a FWHM of 147 nm at 1:1 ratio.The device based on this ratio had a narrow EQE spectrum in red region with a FWHM of 197 nm,and the maximum EQE is 6.89%.Then,PolyTPD and PTAA were selected due to their low absorption in visible range,which were mixed with SBDTIC,respectively,and their blends were narrowly absorbed in red region.The absorption spectrum of PolyTPD:SBDTIC had a FWHM of 119 nm.Based on this,the organic photodetector obtained the highest EQE of 10.45%and the highest specific detectivity of 1.42e13 Jones.Finally,PolyTPD,DIBSQ and SBDTIC were mixed and the ternary blend had a narrow absorption in red region.By changing the proportion of PolyTPD,FWHM of about 160 nm was obtained in red region.Devices based on ternary blends had the highest EQE of 11.30%at-0.5 V.All of the abovementioned photodetectors had strong absorption and high responsivity in red region,but low light absorption and weak responsivity outside red region,that is,they all had better spectral rejection ratios.Which indicated that the narrowband response of organic photodetector in red region can be achieved by these methods in this thesis,and the organic photodetector based on this non-fullerene material SBDTIC has good potential in color imaging.