Study On Cathode Interface Of Non-fullerene Organic Solar Cell

Organic solar cells(OSCs)have gained popularity in recent years due to their low manufacturing costs,ability to be solution-ready,and light weight.As research progresses,it becomes increasingly clear how OSCs function,and technology’s performance keeps getting better.The design and synthesis of active layer materials,device structure optimization,active layer morphology optimization,and interface engineering can all be credited with improving device performance.OSCs based on non-fullerene acceptors outperform conventional OSCs based on fullerene acceptors in terms of device performance,making them a popular area of research at the moment.To further increase the power conversion efficiency(PCE)of OSCs based on nonfullerene acceptors,cathode interface engineering can effectively promote the transfer and collection of charge.This paper prepared a series of devices based on binary organic solar cells based on non-fullerene acceptors by doping the device’s original cathode interface and using new materials as the cathode interface layer.The experimental device’s PCE has been somewhat enhanced.The reasons for the PCE improvement of the device are finally discovered after testing and comparing the PCE,external quantum efficiency(EQE),film morphology,and water contact angle of the device before and after the improvement.The specific innovations and research achievements are summarized as follows:(1)The non-fullerene accepter material IT-M,the anode interface layer material PEDOT:PSS,the cathode interface layer material PFN-Br,and the active layer donor material PBDB-T were chosen.The binary organic solar standard cell was created through exploration.The environmentally friendly amino acid organic small molecule material L-arginine was applied to the binary organic solar cells based on PBDB-T:ITM non-fullerene acceptors,and the PFN-Br was modified by doping method,based on the standard device of binary organic solar cells using PFN-Br as the cathode interface layer.Theoretically,L-arginine has a distinct positive and negative potential that favors the development of interfacial dipoles and facilitates the transmission and collection of electrons.After doping,the cathode interface layer’s hydrophilicity increases,allowing for better contact with electrode Al and an increase in the metal electrode’s ability to collect electrons.Finally,the organic solar cell’s PCE is raised from about 10.5 % to about 11.2 % using PBDB-T:IT-M as the active layer and PFN-Br: L-arginine as the cathode interface layer.(2)Small organic molecules containing sulfonic acid were quantitatively calculated using the Gaussian quantization calculation package based on the DFT method.Ultimately,sodium 2,7-naphthalene disulfonate was decided upon as the testing substance.The sodium 2,7-naphthalene disulfonate with sulfonic acid was chosen as the cathode interface layer material based on binary organic solar cell devices without a cathode interface layer.The substance can make excellent contact with electrode Al thanks to its excellent methanol solubility and clear hydrophilicity.The material energy level is also well-matched at the same time.The device using sodium2,7-naphthalene disulfonate as the cathode interface layer has an obviously higher open circuit voltage than the device without one,and the PCE of the device with the cathode interface layer is increased from roughly 6.3 % to roughly 9.1 %.