Investigation Of Triple Cation Perovskite Solar Cells Based On Er³⁺/Mg²⁺ Modified TiO₂ Nanorod Arrays

Control of morphologies of electronic transport layers?ETLs?has a significant impact on the photovoltaic?PV?performance of mesoporous perovskite solar cell?PSC?.This thesis develops Er doping and Mg/Er co-doping TiO₂ nanorods arrays by a hydrothermal method and assembles triple cation perovskite solar cells using the formed TiO₂ nanorods arrays as ETLs.The related PV performance is studied.The details are as follows:1)Er doped TiO₂ nanorod arrays?NRAs?were synthesized via a facile solvothermal method using Tetra-butyl titanate?TBT?and erbium pentahydrate?Er?NO₃?₃·₅H₂O?as Ti and Er sources,respectively.PSC solar cells were fabricated using the synthesized NRAs as ETLs.We studied the influence of the concentration of TBT and the proportion of Er on the morphological properties of the formed TiO₂ nanorod arrays and the PV performance of the assembled PSCs.Under the optimized conditions of 0.04 M of TBT and Er:Ti atom ratio of is20:100,PSCs demonstrated average power conversion efficiency?PCE?of 17.54%,which is higher that of PSCs based on traditional TiO₂ nanoparticle ETLs.2)Mg and Er co-modified TiO₂ nanrod arrays were synthesized for efficient PSCs.The Mg doped c-TiO₂ was used as seeds for hydrothermally 1D TiO₂ nanorod?NR?arrays.Using these seed layers,Mg and Er co-modified TiO₂ rutile nanorod arrays were fabricated via the facile solvothermal method using tetrabutyltitanate?TBT?and Er?NO₃?₃ as Ti and Er precursors,respectively.The electrical behaviors and optical properties of Mg and Er modified titania nanorod ETLs were characterized and examined to understand the mechanisms of underperformance and outperformance in diverse PSC cell PV parameters.The champion Cs_0.05(MA_0.17FA_0.83)_0.95Pb(I_0.83Br_0.17)₃ triple cation PSC cells based on Mg/Er modified TiO₂ nanorod arrays achieves a PCE of 19.11%,presenting short-circuit current density(J_SC)of 22.01 mA cm^-2 and open-circuit voltage?Voc?of 1.08V.