A novel leaves and needles like TiO2 (LNT) electron transfer layer (ETL) as an alternative to meso-porous TiO2 electron transfer layer (ETL) in perovskite solar cell

Abstract

Two perovskite solar cells one with leaves and needles like TiO2 (LNT) and other with meso-porous TiO2 as electron transfer layer (ETL) were fabricated. The perovskite solar cell structure FTO/Compact-TiO2/LNT/ CH3NH3PbBr3/Spiro-OMeTAD/Ag with leaves and needles like TiO2 electron collector, exhibit high efficiency up to 9% being supported by high open-circuit voltage and fill factor up to 0.8 V and 0.89, respectively. The second perovskite solar cell structure FTO/Compact-TiO2/Meso-porous TiO2/CH3NH3PbBr3/Spiro-OMeTAD/Ag with meso-porous TiO2 electron collector, efficiency is 6.2% with open-circuit voltage and fill factor up to 0.77 V and 0.71 respectively. As compared to meso-porous TiO2 electron collector layer, leaves and needles like TiO2 has better electron band alignment with compact TiO2 as hole blocking layer and hence, results in higher efficiency.