Perovskite Solar Cells: Influence of Hole Transporting Materials on Power Conversion Efficiency

Efficient Regular Perovskite Solar Cells Based on Pristine [70]Fullerene as Electron-Selective Contact

[70]Fullerene is presented as an efficient alternative electron-selective contact (ESC) for regular-architecture perovskite solar cells (PSCs). A smart and simple, well-described solution processing protocol for the preparation of [70]- and [60]fullerene-based solar cells, namely the fullerene saturation approach (FSA), allowed us to obtain similar power conversion efficiencies for both fullerene materials (i.e., 10.4 and 11.4 % for [70]- and [60]fullerene-based devices, respectively). Importantly, despite the low electron mobility and significant visible-light absorption of [70]fullerene, the presented protocol allows the employment of [70]fullerene as an efficient ESC. The [70]fullerene film thickness and its solubility in the perovskite processing solutions are crucial parameters, which can be controlled by the use of this simple solution processing protocol. The damage to the [70]fullerene film through dissolution during the perovskite deposition is avoided through the saturation of the perovskite processing solution with [70]fullerene. Additionally, this fullerene-saturation strategy improves the performance of the perovskite film significantly and enhances the power conversion efficiency of solar cells based on different ESCs (i.e., [60]fullerene, [70]fullerene, and TiO2 ). Therefore, this universal solution processing protocol widens the opportunities for the further development of PSCs.

Neutral- and Multi-Colored Semitransparent Perovskite Solar Cells

In this review, we summarize recent works on perovskite solar cells with neutral- and multi-colored semitransparency for building-integrated photovoltaics and tandem solar cells. The perovskite solar cells exploiting microstructured arrays of perovskite “islands” and transparent electrodes—the latter of which include thin metallic films, metal nanowires, carbon nanotubes, graphenes, and transparent conductive oxides for achieving optical transparency—are investigated. Moreover, the perovskite solar cells with distinctive color generation, which are enabled by engineering the band gap of the perovskite light-harvesting semiconductors with chemical management and integrating with photonic nanostructures, including microcavity, are discussed. We conclude by providing future research directions toward further performance improvements of the semitransparent perovskite solar cells.

A New 1,3,4-Oxadiazole-Based Hole-Transport Material for Efficient CH3 NH3 PbBr3 Perovskite Solar Cells

A new hole-transport material (HTM) based on the 1,3,4-oxadiazole moiety (H1) was prepared through a single-step synthetic pathway starting from commercially available products. Thanks to a deep HOMO level, H1 was used as HTM in CH3 NH3 PbBr3 perovskite solar cells yielding an efficiency of 5.8%. The reference HTM (Spiro-OMeTAD), under the same testing conditions, furnished a lower efficiency of 5.1%. Steady-state and time-resolved photoluminescence of the thin films showed good charge-extraction dynamics for H1 devices. In addition, H1 shows a large thermal stability and completely amorphous behavior (as evaluated by thermal gravimetric analysis and differential scanning calorimetry).

Simple biphenyl or carbazole derivatives with four di(anisyl)amino substituents as efficient hole-transporting materials for perovskite solar cells

Power conversion efficiencies of 13.6% and 11.5% were achieved in perovskite solar cells with two simple and readily accessible biphenyl or carbazole derivatives as hole-transporting materials.

Investigation of efficient protocols for the construction of solution-processed antimony sulphide solid-state solar cells

Investigation of efficient protocols for the construction of solution-processed antimony sulphide solid-state solar cells.

Enhanced performance of perovskite solar cells with P3HT hole-transporting materials via molecular p-type doping

Tetrafluoro-tetracyano-quinodimethane (F4TCNQ) was demonstrated to be an effective p-dopant for highly efficient PSCs based on P3HT as a hole-transporting material.

How to regulate energy levels and hole mobility of spiro-type hole transport materials in perovskite solar cells

meta-Substitution is more beneficial to reduce HOMO levels compared with ortho- and para-substitution, while the hole mobility can be improved by ortho-substitution.