Spiro‐OMeTAD:Sb₂S₃ Hole Transport Layer with Triple Functions of Overcoming Lithium Salt Aggregation, Long‐Term High Conductivity, and Defect Passivation for Perovskite Solar Cells

Abstract

The development of a hole transport layer (HTL) with persistent high conductivity, good moisture/oxygen barrier ability, and suitable passivation ability of perovskite defects is very important for achieving high power conversion efficiency (PCE) and long‐term stability of perovskite solar cells (PSCs). However, the state‐of‐the art HTL, lithium bis(trifluoromethanesulfonyl)‐imide (Li‐TFSI)‐doped 2,2′,7,7′‐tetrakis‐(N,N‐di‐p‐methoxyphenylamine)‐9,9′‐spirobifluorene (spiro‐OMeTAD), does not have these abilities. Herein, the incorporation of antimony sulfide (Sb2S3) nanoparticles as a multifunctional additive into spiro‐OMeTAD is demonstrated. The Sb2S3 effectively improve the compactness of composite spiro‐OMeTAD:Sb2S3 HTL by inhibiting the Li‐TFSI aggregation and effectively prevent the infiltration of moisture and oxygen into the perovskite layer, resulting in its high chemical stability. More importantly, Sb2S3 not only improves the conductivity and hole mobility of the spiro‐OMeTAD:Sb2S3 through the oxidation of spiro‐OMeTAD by Sb2S3, but also makes the high conductivity more durable and stable in the atmospheric environment. In addition, Sb2S3 also effectively passivates the perovskite defects and accelerates the charge transfer from perovskite layer to HTL. As a consequence, the optimized PSCs based on spiro‐OMeTAD:Sb2S3 HTL exhibit a much higher PCE (22.13%) than that (19.29%) of the PSCs without Sb2S3 and show a greatly improved stability.

Tailoring the Crystallographic Orientation of a Sb2S3 Thin Film for Efficient Photoelectrochemical Water Reduction

“…On the basis of eq , the conductivity of the Ag:Sb 2 S 3 film was calculated to be (7.89 ± 2.96) × 10 –7 S cm –1 , which is higher than that of the Sb 2 S 3 film ((1.54 ± 0.33) × 10 –7 S cm –1 ) in the direction normal to the Mo substrate. On the basis of eq , the carrier mobility is (0.89 ± 0.67) × 10 –2 cm 2 V –1 s –1 for the Sb 2 S 3 film and (6.13 ± 0.96) × 10 –2 cm 2 V –1 s –1 for the Ag:Sb 2 S 3 film. It is worth noting that, in comparison with the reduction of defect density, the improvement in conductivity and carrier mobility is more remarkable, which can be attributed to the excellent intraribbon carrier transport of Sb 2 S 3 film in the [ hk 1] orientation. where ε 0 represents the vacuum permittivity, ε is the relative dielectric (ε = 6.67), , e is the elementary charge, L is the thickness of the films, J D is the current density, and V b is the applied voltage.…”

“…On the basis of eq 3, the conductivity of the Ag:Sb 2 S 3 film was calculated to be (7.89 ± 2.96) × 10 −7 S cm −1 , which is higher than that of the Sb 2 S 3 film ((1.54 ± 0.33) × 10 −7 S cm −1 ) in the direction normal to the Mo substrate. On the basis of eq 4, 35 the carrier mobility is (0.89 ± 0.67) × 10 −2 cm 2 V −1 s −1 for the Sb 2 S 3 film and (6.13 ± 0.96) × 10 −2 cm 2 V −1 s −1 for the Ag:Sb 2 S 3 film. It is worth noting that, in comparison with the reduction of defect density, the improvement in conductivity and carrier mobility is more (2)…”

A synergistic co-passivation strategy for high-performance perovskite solar cells with large open circuit voltage

“…28,[44][45][46] To evaluate the interfacial charge density and the relationship between the V oc and built-in potential (V bi ) in PSCs, the classical Mott-Schottky (M-S) relation via the capacitance-voltage (C-V) measurements is investigated. 46,47 As shown in Fig. 6c, the V bi values at the intercept C À2 = 0 are 1.03, and 1.12 V for the control and TSTP-CFM devices, respectively.…”

Strategies for high‐performance perovskite solar cells from materials, film engineering to carrier dynamics and photon management

“…Recently, more and more functional materials are used as additives to improve the property of spiro‐MeOTAD, including H 3 PO 4 , 537 CuSCN, 538 CuI, 538 Cu(bpcm) 2 , 539 Cu 1.8 S, 540 Sc 3 N@C 80 , 541 POM@MOF, 542 Mo‐(tfd‐CO 2 Me) 3 , 543 Mo(tfd‐COCF 3 ) 3 , 543 and carbo nanotube, 544,545 which promote the development of high‐efficiency HPSCs. Recently, our group reported multifunctional additives of Sb 2 S 3 546 or PbSO 4 (PbO) 4 547 NPs and P into spiro‐OMeTAD. These NPs some functions as follow: (1) inhibiting the Li‐TFSI aggregation; (2) preventing the infiltration of moisture and oxygen into the perovskite layer; (3) improving the compactness of composite spiro‐OMeTAD; (4) increasing the conductivity and hole mobility of the spiro‐OMeTAD; (5) passivating the perovskite defects; and (6) accelerating the charge transfer from perovskite layer to spiro‐OMeTAD.…”

“…Recently, more and more functional materials are used as additives to improve the property of spiro-MeOTAD, including H 3 PO 4 , 537 CuSCN, 538 CuI, 538 Cu(bpcm) 2 , 539 Cu 1.8 S, 540 Sc 3 N@C 80 , 541 POM@MOF, 542 Mo-(tfd-CO 2 Me) 3 , 543 Mo(tfd-COCF 3 ) 3 , 543 and carbo nanotube, 544,545 which promote the development of high-efficiency HPSCs. Recently, our group reported multifunctional additives of Sb 2 S 3 546 or PbSO 4 (PbO) 4 547 NPs and P into spiro-OMeTAD. These…”