Enhancement Of The Performance Of The Perovskite Solar Cells By Utilizing Additive

Organic-inorganic hybrid perovskite is an ideal material for planar heterojunction solar cells due to good crystal characteristics,low cost,simple synthesis,and it can be processed by solution method.The quality of perovskite film is crucial to the performance of planar heterojunction perovskite solar cells.The thin film with high-quality,low-defect,full coverage can reduce the possibility of carrier recombination and promote the process of carrier transmission.In this paper,we compared two-step spin-coating method with one-step spin-coating method for preparing perovskite film and explored the function of different additive in planar heterojunction solar cells.The detailed contents are as follows.1.Research on the methods that prepared perovskite film.Firstly,we investigated the effects of NH₄Cl additive and the concentration of CH₃NH₃I in two-step spin-coating method.Furthermore,we focused researches on different anions,the concentration and temperature of precursor solution,and the annealing time in one-step spin-coating method.It is found that one-step spin-coating method is better than two-step spin-coating method.Finally we find that the film fabricated with one-step spin-coating method shows the best morphology and exhibits the best photovoltaic performance with corresponding device.2.1-Ethylpyridinium chloride ionic salt（1-ECIS）was selected as additive to reduce roughness and increase substrate coverage in perovskite thin film processed via one-step solution process which is simple and effective.We reported a planar heterojunction perovskite solar cell fabricated from perovskite precursor solution containing pyridine additive.The perovskite films have been characterized by UV-vis,SEM,XRD,and steady-state photoluminescence（PL）As a result,PCE of device fabricated with precursor solution containing 1.00 wt% 1-ECIS additive increases from 2.13%（based on pristine perovskite）to as high as 14.04%.Short circuit current density(J_sc = 20.49 mA/cm²),Open circuit voltage(V_oc = 0.9 V),and Factor（FF = 0.76）were enhanced simultaneously compared to the device with pristine film.3.We reported a planar heterojunction perovskite solar cell fabricated from perovskite precursor solution containing pyridine additive.The perovskite films have been characterized by UV-vis,SEM,XRD,and steady-state photoluminescence（PL）.We manufactured devices with the structure of ITO/PEDOT: PSS/CH₃NH₃PbI₃/PCBM/Al.Lastly,PCE of 7.33% was acquired in the optimal device（containing 1.00 vol%（V/V）pyridine additive）with a Jsc of 14.64 mA/cm²,a Voc of 0.82 V,and an FF of 0.61.