Influence of the Spark Plasma Sintering temperature on the structure and dielectric properties of BaTi(1-x)ZrxO3 ceramics

In this work, structural and dielectric properties of BaTi(1-x)ZrxO3 (BTZ) ceramics prepared by Spark Plasma Sintering (SPS) from powders obtained via Self-propagating High-temperature Synthesis (SHS) are shown to be strongly affected by the sintering temperature. In addition, a post-annealing treatment in air of the as-prepared ceramics leads to a transition from the hexagonal to the tetragonal and cubic phases. The SPS ceramics corresponding to compositions 0.05 ≤ x ≤ 0.20 and obtained at a sintering temperature of 1200 °C exhibit a standard ferroelectric behavior. In contrast, a diffuse phase transition is observed for the case of ceramics sintered at higher temperatures. Finally, the BTZ ceramic containing 5 at.% of Zr displays the best dielectric permittivity and piezoelectric properties as compared to the other compositions taken into account

Theoretical Device Engineering for High‐Performance Perovskite Solar Cells Using CuSCN as Hole Transport Material Boost the Efficiency Above 25%

Recently, perovskite solar cells (PSCs) have achieved remarkable power conversion efficiency (PCE) about 22.6%. While most of the hole transport materials (HTMs) used in PSCs are organic in nature with an issue of instability and high cost. In this paper, copper thiocyanate (CuSCN), a low cost inorganic HTM with excellent thermal and moisture stability, is applied as HTM for perovskite solar cells. The device modeling of PSCs is based on the device structure of FTO/TiO2/MAPbI3/CuSCN/Au. Two interface defect layers, IDL1 as electron transport material (ETM)/absorber interface and IDL2 as absorber/HTM interface, are introduced into the device model in order to study the impact of interface quality on the performance of PSCs. Among all of the parameters, defect density and conduction band offset (CBO) at ETM/absorber interface together with the defect density of absorber influence the device performance appreciably. Upon optimization of all of the parameters, PCE of the device approaches to 25.02%, which is very encouraging. The result shows that lead‐based PSC with CuSCN as HTM is an efficient system due to its enhanced hole transport, high electric conductivity, and improved chemical interaction with absorber. Further, defect density of ETM/absorber interface and absorber layer could be reduced by optimized deposition process