Efficient and thermally stable inverted perovskite solar cells by introduction of non-fullerene electron transporting materials

Abstract

Highly efficient and thermally stable inverted MAPbI3 and FAPbI3−xBrx perovskite planar solar cells are demonstrated by using a N,N′-bis(phenylmethyl)naphthalene-1,4,5,8-tetracarboxylicdiimide (NDI-PM)-based electron transporting material (ETM) instead of a conventional PCBM-based ETM.

Homochiral Asymmetric‐Shaped Electron‐Transporting Materials for Efficient Non‐Fullerene Perovskite Solar Cells

“…NDI-PhE, with the chiral PhE group, showede nergy levels of the electronic states [highest occupied molecular orbital( HOMO) and lowest unoccupied molecular orbital (LUMO)]t hat were comparable to those of NDI-PM with achiral benzylg roups. [29] Based on calculations at the B3LYP/6-311 + G** level using the optimized geometries at B3LYP/6-31G* level, the HOMO and LUMO of NDI-PhE in the gas phase were found to be À6.93 and À3.74 eV,r espectively, and those of NDI-PM were found to be À7.05 and À3.82 eV,respectively.T he conformer of NDI-PhE in the crystalline state also exhibited similar HOMO and LUMO levels (À6.86 and À3.67 eV,r espectively). These results indicate that introducing the chiral PhE group on N-substituted NDI may not significantly affect the levels of electronic states.…”

“…For example, homochiral NDI-PhE exhibits about 35 times highers olubility in DCB than that of achiral N,N'-bis(phenylmethyl)naphthalene-1,4,5,8-tetracarboxylic diimide (NDI-PM) having achiral benzyl groups (0.19 g/100 gD CB). [29] In addition, NDI-PhE exhibits 2.2 times higher solubility than that of PCBM (3.1 g/100 gD CB).…”

“…[51] The void content of NDI-PhE is ar elatively very high 29 %, which is higher than that of fullerene-basedP CBM (25 %) and achiral NDI-PM( 27 %). [29] Figure 1d shows the void shape of NDI-PhE moleculesi nt he crystalline state (see also Figure S2 in the Supporting Information). Most voids are near the asymmetric-shaped PhE groups (see red solid lines in Figure 1d).…”

“…[21][22][23][24][25] In contrast, only af ew classes of electron-transporting materials (ETMs)b ased on small molecules have been reported. [26][27][28][29][30] In anothera pproach, electron transporting layer-free PSCs have been reported. [31] Of the reported small-molecule ETMs, fullerene and its derivatives, such as C 60 , phenyl-C 61 -butyric acid methyl ester (PCBM), and indene-C 60 -bisadduct (ICBA), have been used as standard electron transporters not only for their optimal energyl evel alignment with per-Ad esign strategy is proposed for electron-transporting materials (ETMs)w ith homochiral asymmetric-shaped groups for highly efficient non-fullerene perovskite solar cells (PSCs).…”

Quaternary Iron Nickel Cobalt Selenide as an Efficient Electrocatalyst for Both Quasi‐Solid‐State Dye‐Sensitized Solar Cells and Water Splitting

“…The electricalc onductivity of materials plays ak ey role in the electrocatalytic performance. [13] The conductivity (s 0 )o f Fe 0.37 Ni 0.17 Co 0.36 Se and NiCo 2 Se 4 was characterizedb yc urrentvoltage (I-V)m easurements, as shown in Figure 6b. The conductivity,d etermined from the slopes of the curvesi nF ig-ure 6b, was 0.422 and 0.374 mS cm À1 for Fe 0.37 Ni 0.17 Co 0.36 Se and NiCo 2 Se 4 ,r espectively.Q uaternary Fe 0.37 Ni 0.17 Co 0.36 Se evidently has ahigher conductivitythan ternary NiCo 2 Se 4 .The synergistic effect of the four metal elements in quaternary Fe 0.37 Ni 0.17 Co 0.36 Se is more remarkable than in ternary NiCo 2 Se 4 , and accounts for the enhancement in conductivity between the ternary and quaternary selenides.…”