Efficient and ultraviolet durable planar perovskite solar cells via a ferrocenecarboxylic acid modified nickel oxide hole transport layer

Abstract

Planar perovskite solar cells (PSCs) that use nickel oxide (NiO) as a hole transport layer have recently attracted tremendous attention because of their excellent photovoltaic efficiencies and simple fabrication. However, the electrical conductivity of NiO and the interface contact properties of the NiO/perovskite layer are always limited for the NiO layer fabricated at a relatively low annealing temperature. Ferrocenedicarboxylic acid (FDA) was firstly introduced to modify a p-type NiO hole transport layer in PSCs, which obviously improves the crystallization of the perovskite layer and hole transport and collection abilities and reduces carrier recombination. PSCs with a FDA modified NiO layer reached a PCE of 18.20%, which is much higher than the PCE (15.13%) of reference PSCs. Furthermore, PSCs with a FDA interfacial modification layer show better UV durability and a hysteresis-free effect and still maintain the original PCE value of 49.8%after being exposed to UV for 24 h. The enhanced performance of the PSCs is attributed to better crystallization of the perovskite layer, the passivation effect of FDA, superior interface contact at the NiO/perovskite layers and enhancement of the electrical conductivity of the FDA modified NiO layer. In addition, PSCs with FDA inserted at the interface of the perovskite/PCBM layers can also improve the PCE to 16.62%, indicating that FDA have dual functions to modify p-type and n-type carrier transporting layers.

Efficient Inverted Planar Perovskite Solar Cells Using Ultraviolet/Ozone‐Treated NiOx as the Hole Transport Layer

“…Furthermore, the external quantum efficiency (EQE) spectra in Figure a has illustrated the detail of the improved photovoltaic performance of UVO‐NiO x based PSCs from the spectroscopic response, where the EQE has been gradually enhanced in 350–500 nm and 600–700 nm regions with the increasing exposure time of UVO treatment on NiO x film. The spectrum has shown a broad plateau around 90% in the range of 350–750 nm, which is consistent with previous literatures, where the maximum values are all above 90% for MAPbI 3 ‐based PSCs . The integrated J SC of the champion device can be up to 22.55 mA cm −2 , consisting with the measured J SC of 23.39 mA cm −2 by the J–V measurements.…”

From Bulk to Surface: Sodium Treatment Reduces Recombination at the Nickel Oxide/Perovskite Interface

“…The introduction of different surface treatments is an extremely promising approach to improve PSCs performances. For example, monoethanolamine, F6TCNNQ, and ferrocenecarboxylic acid were successfully applied as interlayers in NiO based devices. However, the formation of an organic monolayer is commonly a delicate process.…”

“…Wavelength selectivity of the PL emission was achieved by coupling a tunable liquid crystal filter in front of the camera. The setup was calibrated to absolute photon numbers with light sources of known fluences, thus enabling to estimate the quasi Fermi level splitting from the generalized Planck law using the high‐energy tail fit method …”

Zn0.8Cd0.2S@PCBM Hybrid as an Efficient Electron Transport Layer for Air‐Processed p‐i‐n Planar Perovskite Solar Cells: Improvement of Interfacial Electron Transfer and Device Stability

“…For devices with PCBM and ZCS@PCBM ETL, the R rec is determined to be 240.7 and 363.1 Ω, respectively. Larger R rec means less current leakage and suppressed charge recombination at the interface . Moreover, EIS measurement was carried out under various bias voltages from 0.6 to 1.0 V in the dark (Figure S7, Supporting Information).…”