Research On The Effect Of Perovskite Nanostructure On The Properties Of Solar Cells

Perovskite solar cells have attracted keen attention because of their low-cost and rapid increase in power conversion efficiency(PCE)in the last few years.In perovskite solar cells,it is necessary to research on the light absorption characteristics and carrier transport properties of the perovskite absorber to optimize the optoelectronic properties of perovskite solar cells.In addition,interface engineering needs to be used to improve contact between layers to reduce recombination and increase the injection and extraction of carriers.It was found that the morphology and nanostructure of perovskite thin film affect the optical absorption properties and carrier transport properties of the films,which have a significant influence on the photovoltaic performance of solar cell.At the same time,the perovskite nanostructures can affect the interfacial carrier separation and recombination,thus affecting the transmission performance of solar cells carrier.In this paper,the mesoporous perovskite solar cells were made using the two-step solution method.Via using solvent engineering,the morphology and nanostructure of perovskite thin film can be well-controlled by adjusting the concentration of the aprotic solvent DMF.In addition,the effect of nanostructures of perovskite thin films on the solar cells performance was investigated.When the concentration of DMF in IPA was 15 μL/mL,the perovskite film with island structure was fabricated,the best device was obtained,the average efficiency was increased by 1.28%.When the concentration of DMF was over 25 μL/mL,one-dimensional nanowire perovskite was fabricated.The best device with nanowires was obtained with 50 μL/mL,which was due to the decrease of the carriers recombination between the hole transport layer and the electron transport layer with high surface coverage.The poor contact at the perovskite/carbon interface was the main cause for the low photovoltaic performance for carbon-based PSCs.Herein,the porous perovskite thin film was easily fabricated by the dissolution-recrystallization process and the carbon was infiltrated into the pores of nano wire structure.The process was employed to provide better contact at the perovskite/carbon interface.Owing to the better contact,the charge separation at the perovskite/carbon interface was facilitated and the hole migration from the perovskite to carbon was improved.The best devices employing porous perovskite thin film show 7.21%power conversion efficiency,photocurrent density of 19.07 mA/cm2,voltage of 0.86 V,and fill factor of 43.9%.