The Performance Of Organic Solar Cell Devices Based On Non-Fullerene Acceptor Materials

In recent years,organic solar cells have become one of the research hotspots in the field of solar cells because of its relatively simple preparation process,relatively inexpensive raw materials,variability of material design,and the possibility of large-area preparation.Taking laminated organic solar cells as an example,the photoelectric conversion efficiency has exceeded 14%.Although industrialization is currently difficult in China,its application prospects are still very promising with more in-depth research on organic solar cells.The active layer plays a decisive role in the photoelectric conversion of solar cells.The sudden emergence of non-fullerene materials makes the active layer material design diversified.In this dissertation,non-fullerene materials are used as the research object,a series of non-fullerene materials are designed and synthesized,and their photovoltaic properties are characterized.From this study,some scientific problems of non-fullerene materials are studied.The design of organic solar cell active layer provides ideas.The main results are as follows:1.The narrow-band-gap donor polymers PDPP3T,PDPP4T,PDPP5T and PDPP6T with diketopyrrolopyrrole(DPP)as the core are matched with the non-fullerene acceptor material ITIC to prepare organic solar cell devices.Among them,the optimal efficiency of the battery device with the PDPP5T as the electron donor reached 4.1%,the external quantum efficiency reached 0.4,and the photoelectric conversion rate of the battery device based on the PDPP3T as the donor material was only 1.9%.On this basis,we further explored the micro-morphology of the active layer of the battery device and discovered that the poor intersolubility of the acceptor polymer leads to defects in the bulk heterojunction structure,which affects the performance of the battery device.2.Some non-fullerene small molecule receptors(trans-PBI,cis-PBI)were constructed with Perylene Diimides(PBI)as the core,the photoelectric conversion efficiency(PCE)of 0.13%and 7.6%were respectively obtained in the battery devices based on their electron acceptors.The rate of high PCE was 6.3%for all-polymer solar cell devices constructed with cis-polyPBI and PBDB-T.The electron mobility measured by FET was 8.6×10-3 cm2 V-1s-1,3.2×10-3cm2 V-1s-1,and 1.2×10-2cm2 V-1s-1,respectively.Distortion of the cis-PBI and cis-polyPB mobility of the conjugated backbone acceptor material indicates that the small-angle twisted conjugated backbone has little effect on the electron mobility of the acceptor.Through the study of device performance and morphology,defects such as mismatched carrier mobility and too small phase separation size will reduce the performance of solar cells.