In Situ Formation of Compact PbI₂ Shell Boosts the Efficiency and Thermostability of Perovskite Solar Cells

Abstract

Judicious tailoring of a robust interlayer is central to maintain the durable operation of optoelectronic devices. In this paper, an ultrathin, compact, and uniform PbI2 shell on the surface of perovskite via the method of ZnI2 aided in situ transformation is produced. The resultant PbI2 interlayer can prolong the excited‐state lifetime of perovskite and attenuate the recombination kinetics of separated charges, leading to an improvement of power conversion efficiency up to 22.5% for perovskite solar cells (PSCs) at the AM 1.5G conditions. Moreover, the PSC with PbI2 interlayer exhibits an enhanced thermostability, retaining 87% of initial efficiency after aging at 60 °C for 1000 h.

Impact of Polymeric Hole‐Selective Layers on Chemical Inductance in Inverted Perovskite Solar Cells

“…The higher (bright) contrasts on the surface are ascribed to the unreacted PbI2 that is present on the perovskites. 33 To evaluate the influence of the HTLs on PV performance, we fabricated inverted PSCs with a device configuration of FTO/HTL/CsFAMA/6,6-phenyl-C61-butyric acid methyl ester (PCBM)/bathocuproine (BCP)/Ag. The HTL was selected from PEDOT:PSS, P3HT, and PTAA, and the current density-voltage (J-V) characteristics are shown (Figure 2b), and the relevant PV parameters are summarized (Table 1).…”

“…The higher (bright) contrasts on the surface are ascribed to the unreacted PbI 2 that is present on the perovskites. [ 31 ] As the photo‐induced charge‐transfer properties are highly dependent on the perovskite surface quality, tapping‐mode atomic force microscopy (AFM) was used to observe the perovskite surface morphology and roughness on different HTLs (Figure S4, Supporting Information). The evaluated root mean square (RMS) roughness value of the perovskite layer on PEDOT: PSS, PTAA, and P3HT, are 20.44, 16.89, and 17.61, respectively, suggesting that the perovskite grown on PTAA and P3HT has a smoother and compact morphology as compared with that of the perovskite on PEDOT: PSS.…”

Diluted-CdS Quantum Dot-Assisted SnO2 Electron Transport Layer with Excellent Conductivity and Suitable Band Alignment for High-Performance Planar Perovskite Solar Cells

“…Stability is a key issue in evaluating PSC performance. Since PSCs are sensitive to moisture and heat, both the perovskite and hole transport layer degrade easily under water erosion and heat stress . Therefore, we compare the stability of the unpackaged PSCs.…”

“…Since PSCs are sensitive to moisture and heat, both the perovskite and hole transport layer degrade easily under water erosion and heat stress. 54 Therefore, we compare the stability of the unpackaged PSCs. As shown in Figure 7c,d, the PCE of PSCs based on CdS (1.0%)−SnO 2 ETLs dropped only from 20.78 to 18.45%, which was 88.79% of the initial efficiency after being placed at a relative humidity of 40% (23 °C) without packaging for 600 h. While, the PCE of PSCs based on SnO 2 ETLs dropped from 18.81 to 10.90%, which was 57.95% of the initial efficiency under the same storage condition.…”

Singular Time‐Dependent Photoconductivity Response of MAPbI3 Samples Deposited by Vacuum Processing on Different Substrates

“…[26][27][28] On the other hand, there are many reports identifying that an excess of PbI 2 formed at the interface between the charge extracting layer and the evaporated perovskite film has effects on the eventual solar cell performance. [29,30] The influence of the substrates, especially TaTm, C 60 , and PbI 2 , on the OIP properties is a subject that deserves further investigation.…”