Study On The Inverted Perovskite Solar Cell Based On NiO_x Interface Modification

Traditional fossil energy sources are exhausted and cause great pollution to the environment.In order to protect the environment of the earth,clean energy should be used as soon as possible.Perovskite solar cells?PSCs?have the advantages of simple preparation process,low preparation cost and high device efficiency.The preparation process of p-i-n PH-PSC is simpler than that of the n-i-p PH-PSC,and the hysteresis effect of p-i-n PH-PSC is negligible.However,the power conversion efficiency?PCE?of p-i-n PH-PSC is lower than of the n-i-p PH-PSC.Some methods were selected to improve the PCE of PSCs,such as,optimizing the device structure,additive engineering,controlling the temperature of substrate and solution,and anti-solvent washing technology.In this thesis,interface engineering was used to improve PCE of p-i-n PH-PSC,the main content can be divided into three parts as follows.?1?Cellulose was used to modify the surface of NiO_x.SEM,J-V characteristic curve,IPCE,surface wettability,UV,PL,UPS were characterized to explore the effect of cellulose interface modification layer on device performance.It was found that cellulose can improve the contact between NiO_x layer and perovskite,and therefore improve the uniformity of the perovskite film,leading to the increase in J_SC of PSCs.After cellulose modification,the work function of NiO_x is improved.Therefore,the hole extraction ability was enhanced and the V_OC of the device increased.In addition,process conditions of the spin-coating of cellulose was optimized,resulting in a PCE over 14%.?2?PVA was used to modify the surface of NiO_x.The results of the J-V characteristics,IPCE,SEM,UPS,XPS,hole-only device,PL and wettability demonstrated that PVA can improve the wettability of perovskite precursor on the surface of NiO_x and the interface contact with the perovskite layer,resulting in perovskite film with reduced defect density and improved hole mobility.At the optimum concentration of PVA at 0.75 mg/mL,the device efficiency increased from12.66%to 15.83%compared to the comparison device,increased by 25.03%.?3?Sol-gel method was used to perpare NiO precursor solution.The solution concentration and conditions of spin-coating techinque were optimized.Experimental results showed that 15 mg/mL was the optimal concentrion of NiO solution,resulting in a PCE of 14.08%.In addition,ethanolamine was used to modify the surface of NiO.Based on NiO with ethanolamine modification,the grain size of the perovskite surface increased greatly,leading to the increase in PCE of PSCs.