Spontaneously supersaturated nucleation strategy for high reproducible and efficient perovskite solar cells

Trap State Passivation by Rational Ligand Molecule Engineering toward Efficient and Stable Perovskite Solar Cells Exceeding 23% Efficiency

“…Consequently, it is highly expected to minimize the trap-assisted nonradiative recombination losses via improving perovskite film quality.The traditional solution method with fast crystallization and high-temperature annealing process would inevitably lead to a variety of defects in perovskite bulk and at the surfaces and grain boundaries (GBs). [7][8][9] Most defects in the bulk of perovskite films are shallow-level defects, while most defects at the surface and GBs of perovskite films are deep-level defects, which is detrimental to device performance through capturing carriers. [6,10,11] Moreover, these defects would provide pathways for ion migration, which results in efficiency and stability losses.…”

(FA0.83MA0.17)0.95Cs0.05Pb(I0.83Br0.17)3 Perovskite Films Prepared by Solvent Volatilization for High‐Efficiency Solar Cells

“…The intermediate phase slows down perovskite nucleation and increases the grain sizes, which is conducive to the formation of dense films. [ 48 ] The grain sizes of the final films after annealing increase with the increase in the MACl amount (Figure 2d,h,l,p). The grain sizes of the films prepared with FAI of 1, 1.1, 1.2, and 1.4 m are 100, 180, 250, and 400 nm, respectively (Figure S2a–d, Supporting Information).…”

“…It was reported that MACl caused precipitation in the solution of MAI and PbI 2 in 2ME, and the precipitation was studied by XRD, and the precipitation contains PbI 2 ‐like intermediate phase, MAPbI 3 phase. [ 44–48 ] Excess MACl leads to precipitation due to the strong coordination with Pb 2+ . [ 44–48 ] Similarly, we think our precipitation in this work contains PbI x Br 2– x ‐like intermediate phase, MA x FA y Cs z PbBr m I 3– m phase, MA x FA y Cs z PbCl l I m Br n phase, and MA x FA y Cs z PbCl 3 phase.…”

“…In our previous work, we used MA in 33 wt% ethanol (MA ethanol) to redissolve the precipitation caused by MACl in the solution of MAI and PbI 2 in 2ME. [ 48 ] Therefore, we think MA/FA cations coordinate with PbI 2 to shift the balance of iodoplumbate complexes by changing the coordination number of PbI 2 in the solution to redissolve the precipitation.…”

“…When the annealing time is 1 min, (101) and (202) crystal plane crystallinity decreased, and the two scattering rings exhibit preferred crystal orientation growth (Figure 3j). [ 48 ]…”