Synergistic defect passivation and phase stabilization enable highly efficient wide-bandgap perovskite solar cells and tandems

Lead-free tin perovskite solar cells

Photovoltaics literature survey (No. 181)

Crossing Up Charge Extraction Layers

Organic-inorganic metal halide perovskites are a new type of photovoltaic material, they have attracted wide attention and made excellent progress in recent years. The power conversion efficiency of a single-junction perovskite solar cell has been increased to 25.2% just within a decade. Meanwhile, crystalline silicon solar cells account for nearly 90% of industrialized solar cells and have a maximum efficiency of 26.7%, approaching to their theoretical limit. It is more difficult to further improve the efficiency of single junction solar cells. It has been shown that multi-junction tandem solar cells prepared by stacking absorption layers with different bandgaps can better use sunlight, which is one of the most promising strategies to break the efficiency limitation of single-junction solar cells. Due to the bandgap tunability and low-temperature solution processability, perovskites stand out among many other materials for manufacturing multi-junction tandem solar cells. Wide bandgap perovskites with a bandgap of 1.63 eV or above have been combined with narrow band gap inorganic absorption layers such as silicon, copper indium gallium selenide, cadmium telluride or narrow bandgap perovskite to produce high efficiency tandem solar cells. In addition to the promoting of the efficiency improvement of solar cells, the wide bandgap perovskites have broad applications in photovoltaic building integration and photocatalytic fields. Therefore, it is very important to explore and develop high quality wide bandgap perovskite materials and solar cells. Unfortunately, the wide bandgap perovskites have several intrinsic weaknesses, including being more vulnerable to the migration of halogen ions under being illuminated, more defects, and greater possibility of energy level mismatching with the charge transport layers than the narrow bandgap counterparts, which limits the further development of the wide bandgap perovskite solar cells. In this review, the development status of wide bandgap perovskite solar cells is summarized and corresponding strategies for improving their performance are put forward. Furthermore, some personal views on the future development of wide bandgap perovskite solar cells are also presented here in this paper.

Hole and electron transport materials: A review on recent progress in organic charge transport materials for efficient, stable, and scalable perovskite solar cells

Unraveling the Impact of Halide Mixing on Crystallization and Phase Evolution in CsPbX3 Perovskite Solar Cells

Photovoltaics literature survey (no. 182)

High-performance methylammonium-free ideal-band-gap perovskite solar cells

Reduced-Dimensional α-CsPbX3 Perovskites for Efficient and Stable Photovoltaics

Photovoltaics literature survey (no. 149)

Interfacial engineering of a thiophene-based 2D/3D perovskite heterojunction for efficient and stable inverted wide-bandgap perovskite solar cells

Decoupling the effects of defects on efficiency and stability through phosphonates in stable halide perovskite solar cells

Tin Perovskite Solar Cells Are Back in the Game

Self-assembled monolayers (SAMs) have displayed unpredictable potential in efficient perovskite solar cells (PSCs). Yet most of SAMs are largely suitable for pure Pb-based devices, precisely developing promising hole-selective contacts (HSCs) for Sn-based PSCs and exploring the underlying general mechanism are fundamentally desired. Here, based on the prototypical donor-acceptor SAM MPA-BT-BA (BT), oligoether side chains with different length (i.e., methoxy, 2-methoxyethoxy, 2-(2-methoxyethoxy)ethoxy group) were custom-introduced on the benzothiadiazole unit to produce the target SAMs with acronyms MPA-MBT-BA (MBT), MPA-EBT-BA (EBT), and MPA-MEBT-BA (MEBT), respectively, and acting as HSCs for efficient Sn-Pb PSCs and all-perovskite tandems. The introduction of oligoether side chains enables HSCs effectively accelerate hole extraction, regulate the crystal growth and passivate surface defects of Sn-Pb perovskites. In particular, benefiting from the enhanced Sn-Pb perovskite film quality and the suppressed interfacial non-radiative recombination losses, EBT-tailored LBG devices yield a champion efficiency of 23.54%, enabling 28.61% efficient monolithic all-perovskite tandems with an impressive VOC of 2.155 V and excellent operational stability as well as 28.22%-efficiency 4-T tandems.

Reducing carrier transport barrier in anode interface enables efficient and stable inverted mesoscopic methylammonium-free perovskite solar cells