High efficiency planar-type perovskite solar cells with negligible hysteresis using EDTA-complexed SnO2

Abstract

Even though the mesoporous-type perovskite solar cell (PSC) is known for high efficiency, its planar-type counterpart exhibits lower efficiency and hysteretic response. Herein, we report success in suppressing hysteresis and record efficiency for planar-type devices using EDTA-complexed tin oxide (SnO2) electron-transport layer. The Fermi level of EDTA-complexed SnO2 is better matched with the conduction band of perovskite, leading to high open-circuit voltage. Its electron mobility is about three times larger than that of the SnO2. The record power conversion efficiency of planar-type PSCs with EDTA-complexed SnO2 increases to 21.60% (certified at 21.52% by Newport) with negligible hysteresis. Meanwhile, the low-temperature processed EDTA-complexed SnO2 enables 18.28% efficiency for a flexible device. Moreover, the unsealed PSCs with EDTA-complexed SnO2 degrade only by 8% exposed in an ambient atmosphere after 2880 h, and only by 14% after 120 h under irradiation at 100 mW cm−2.

SrTiO3/Al2O3‐Graphene Electron Transport Layer for Highly Stable and Efficient Composites‐Based Perovskite Solar Cells with 20.6% Efficiency

“…The photocurrent density versus light intensity (J SC -I) plots follow the power law, i.e., J SC ≈ I β (Figure 5a). [36] From Figure 5b, the values of n are 1.17 and 1.07 for PSCs with mp-TiO 2 and mp-AG, respectively, indicating that fewer trap states and less recombination with the mp-AG based cell. β ≈ 1.0 indicates no space charge effect, and smaller deviation from 1.0 is related to less nongeminate recombination and thus efficient extraction of charge carriers.…”

Chlorine‐modified SnO2 electron transport layer for high‐efficiency perovskite solar cells

“…Figure S3 shows the dark current‐voltage ( I ‐ V ) curves of the single‐electron devices. Obviously, the curve can be divided into three regions in figure S3: the first is an ohmic region, where the current increases linearly with the increase of voltage; the second is the trap‐filling region, where the current increases suddenly with the increase of voltage; third, the kink point defined as the trap‐filled‐limit voltage ( V TFL ), and n t is obtained from the following formula: where L is the perovskite layer thickness, e is the electron charge, ε 0 is the vacuum permittivity, and ε is the relative dielectric constant of the perovskite. The corresponding n t for the perovskite films deposited on pristine SnO 2 and SnO 2 ‐Cl ETLs is 1.84 × 10 14 and 8.25 × 10 13 cm −3 , respectively.…”

Realizing Stable Artificial Photon Energy Harvesting Based on Perovskite Solar Cells for Diverse Applications

“…A high Nb doping shifts the conduction band toward the vacuum energy, according to the UPS results (Figure S11f, Supporting Information). As demonstrated in Figure S14 (Supporting Information), when the absorber is invariant, it usually improves the electron transport and leads to lesser V oc loss 40. However, a further shift would render the ETL conduction band higher than that of the perovskite, and blocks the electron transport instead 41.…”