Stable and Reproducible 2D/3D Formamidinium–Lead–Iodide Perovskite Solar Cells

Abstract

2D perovskite-stabilized FACsPbI 3 (FA = formamidinium) perovskite solar cells were fabricated in both normaltype and inverted-type architectures. While the normal-type devices exhibited a high power conversion efficiency of 20.2%, their reproducibility was limited. On the other hand, the inverted-type devices exhibited an efficiency of 18.2% with a greater stability and higher reproducibility than those of the normal-type devices. The reduced reproducibility of the normal-type devices was associated with the crack formation on the perovskite films during a spin-coating process. The hardness of both the perovskite and the sublayer was directly linked to the crack formation. Inverted-type 2D/3D FACsPbI 3 with ozone-treated poly(triarylamine) as sublayer exhibited the highest phase stability owing to the hydrophobic nature of poly(triarylamine) and improved energy level alignment upon an ozone treatment. In addition, strong interaction between phenethylamine cations of the 2D perovskite and of the 3D FACsPbI 3 crystal at grain boundaries contributed to the high phase stability.

Denatured M13 Bacteriophage‐Templated Perovskite Solar Cells Exhibiting High Efficiency

“…Raising the temperature above 90°C led to the evaporation of the solvents as well as the total denaturing of the M13 bacteriophage, so 90°C was the most optimal temperature. [58,59] Moreover, it is worth noting that the hysteresis of the virus-added PSCs was lower than that of the reference devices and the hysteresis index decreased with the increase in the temperature ( Figure S4, Supporting Information). Though the improvement is marginal, this may indicate enhanced passivation effect arising from reduced trapped charge.…”

The Effect of Constituent Ratios and Varisized Ammonium Salts on the Performance of Two‐Dimensional Perovskite Materials

“…Snaith and co‐workers prepared 2 D–3 D heterostructured butylammonium–cesium–formamidinium lead halide perovskite devices to afford a high PCE of 17.5±1.3 %, which is sustained at 80 % of the initial PCE after 1000 h in air and about 4000 h when encapsulated . In addition, 2 D perovskite materials based on other organic ammonium salts have also been developed successively, such as mixed‐dimensional (MD) (IC 2 H 4 NH 3 ) 2 (CH 3 NH 3 ) n −1 Pb n I 3 n +1 perovskites, 2 D/3 D hybrids (CA 2 PbI 4 /MAPbI x Cl 3− x ) perovskite, 2 D/3 D (HOOC(CH 2 ) 4 NH 3 ) 2 PbI 4 /CH 3 NH 3 PbI 3 perovskite, and so on …”

“…Although many 2 D perovskites with high humidity stability and enhanced PCE have been reported, research into the factors that influence the PCE and moisture resistance of 2 D perovskites has been very limited . Hence, we studied the crystal structures, film morphology, optical properties, photovoltaic properties, and humidity stability of 2 D perovskites based on different 2 D constituent ratios and varisized ammonium salts.…”

“…[33] In addition, 2D perovskite materials based on other organic ammoniums alts have also been developed successively,s uch as mixed-dimensional (MD) (IC 2 H 4 NH 3 ) 2 (CH 3 NH 3 ) nÀ1 Pb n I 3n + 1 perovskites, 2D/3 D hybrids( CA 2 PbI 4 /MAPbI x Cl 3Àx )p erovskite, 2D/3 D (HOOC(CH 2 ) 4 NH 3 ) 2 PbI 4 /CH 3 NH 3 PbI 3 perovskite, and so on. [36][37][38][39][40][41][42][43] Although many 2D perovskites with high humidity stability and enhanced PCE have been reported,r esearch into the factors that influence the PCE and moisture resistance of 2D per-Two-dimensional perovskite solar cells (PSCs) with high moisture resistanceare akey topic in the photovoltaic field. However,t heir lower power conversion efficiencies (PCEs) in comparison to 3D PSCs is still an urgentp roblem to be solved.…”

“…ovskitesh as been very limited. [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] Hence,w es tudied the crystal structures,f ilmm orphology, optical properties, photovoltaic properties, and humidity stability of 2D perovskites based on different 2D constituent ratios and varisized ammonium salts. As ar esult, it can be found that the when n is larger and ammonium salt size is smaller,t he obtained 2D perovskite devicesd isplay better photovoltaic performances, whereas their humidity stabilityd ecreases.…”