Application And Performance Of Organic Semiconductors In The Interface Of Perovskite Solar Cell

Perovskite solar cells(pero-SCs)have received widespread attention due to its superb optoelectronic properties and low cost.At present,the certification efficiency of pero-SCs has reached 25.2%,which has reached the efficiency requirements for commercialization of solar cells.It was expected to replace silicon-based solar cells as the third-generation solar cells in the future.Though,much progress haved been made for the pero-SCs,there are still many factors limiting the further enhancement for the device performance such as defects on the surface of perovskite,interface energy level mismatch and device long-term stability issues.Based on the above,we systematically studied the effects of organic semiconductor interface layer on perovskite crystal growth,surface defects,effect on the morphology of the transport layer,and interfacial energy levels with the device.The specific research is as follows:1.Through precise design,a fullerene derivative(PCBB-S-N)containing thiophene and amino group was synthesized.Both the experiments and theoretical calculations proved that PCBB-S-N has a "targeted therapy" effect on the perovskite interface.Thiophene on PCBB-S-N can passivate uncoordinated lead ion defects in the surface of perovskite film and tertiary amino groups can increase the ability of perovskite film by blocking water molecules further entering perovskite.When PCBB-S-N is used as an interlayer between the perovskite and the electron transport layer PCBM,it can effectively improve the morphology of the PCBM film.In the end,the efficiency of pero-SCs using PCBB-S-N as a media layer reached 21.08%.At the same time,the humidity and thermal stability of pero-SCs have also obviously improved.2.The concept of iso genesis strategy was first proposed and proved to be practical in pero-SCs.By using a polymer as hole transfer layer(HTL)which is consistent with the polymer doped in the chlorobenzene(CB)anti-solvent assistant the growth of perovskite film,an efficient and stable all inorganic pero-SCs is prepared.The polymer doped in the anti-solvent can increase the size of the perovskite grains and passivate the grain boundaries in the perovskite film.In addition,the polymer HTL is consistent with the polymer in anti-solvent,which not only can form perfect interface contact between the surface of the perovskite and the HTL,but also form a continuous hole transport channels to improve hole transport capacity.As a result,the all-inorganic CsPbI2Br device prepared by the isogenesis strategy achieved an efficiency as high as 16.40%,and the humidity,thermal,and light-soaking stability were all significantly improved.