Implementing Lattice and Energy Level Matching to Optimize Buried Interfaces for High-Performance Perovskite Solar Cells.

In n-i-p type perovskite solar cells (PSCs), mismatches in energy level and lattice at the buried interface is highly detrimental to device performance. Here, thin PbS interconnect layer in situ coating on the SnO surface is grown. The function of PbS at the interface is different from the commonly used function of crystalline seeds in perovskite bulk.

In Situ PL Probes the Effect of 2D SnSe Nanosheets on the Crystallization Process of CsPbIBr Perovskite Solar Cells.

Reducing defects in the active layer is important for improving the crystalline quality of all-inorganic perovskite solar cells (PSCs). Exploring novel additives is one of the most promising approaches to minimize active layer defects. In this work, two-dimensional (2D) SnSe nanosheets with excellent optoelectronic properties are prepared using an ultrasonic exfoliation method.

Synergistic Passivation on Buried Interface for Highly Efficient and Stable p-i-n Perovskite Solar Cells.

The properties of an interface at the hole transport layer (HTL)/perovskite layer are crucial for the performance and stability of perovskite solar cells (PVSCs), especially the buried interface between HTL and perovskite layer. Here, a molecular named potassium 1-trifluoroboratomethylpiperidine (3FPIP) assistant-modified perovskite bottom interface strategy is proposed to improve the charge transfer capability and balances energy level between HTL and perovskite. BF in the 3FPIP molecule interacts with undercoordinated Pb to passivate iodine vacancies and enhance PVSCs performance.

Biomaterial Improves the Stability of Perovskite Solar Cells by Passivating Defects and Inhibiting Ion Migration.

With the rapid improvement of power conversion efficiency (PCE), perovskite solar cells (PSCs) have broad application prospects and their industrialization will be the next step. Nevertheless, the performance and long-term stability of the devices are limited by the defect-induced nonradiative recombination centers and ions' migration inside the perovskite films. Here, usnic acid (UA), an easy-to-obtain and efficient natural biomaterial with a hydroxyl functional group (-OH) and four carbonyl groups (-C═O) was added to MAPbI perovskite precursor to regulate the crystallization process by slowing the crystallization rate, thereby expanding the crystal size and preparing perovskite films with low defect density.

An MBene Modulating the Buried SnO/Perovskite Interface in Perovskite Solar Cells.

The interface of perovskite solar cells (PSCs) plays an important role in transferring and collecting charges. Interface defects are important factors affecting the efficiency and stability of PSCs. Here, the buried interface between SnO and the perovskite layer is bridged by two-dimensional (2D) MBene, which improves charge transfer.

-Toluenesulfonic Acid Modified Two-Dimensional ZrSe as a Hole Transport Layer for High-Performance Organic Solar Cells.

Two-dimensional (2D) materials have attracted attention due to their excellent optoelectronic properties, but their applications are limited by their defects and vacancies. Surface modification is an effective method to restore their performance. Here, ZrSe is modified with conductive polymer -toluenesulfonic acid (PTSA).

Improved Air Stability for High-Performance FACsPbI Perovskite Solar Cells via Bonding Engineering.

Despite the fact that perovskite solar cells (PSCs) are widely popular due to their superb power conversion efficiency (PCE), their further applications are still restricted by low stability and high-density defects. Especially, the weak binding and ion-electron properties of perovskite crystals make them susceptible to moisture attack under environmental stress. Herein, we report an overall sulfidation strategy via introduction of 1-pentanethiol (PT) into the perovskite film to inhibit bulk defects and stabilize Pb ions.

Synergetic Regulation of Interface Defects and Carriers Dynamics for High-Performance Lead-Free Perovskite Solar Cells.

Severe nonradiative recombination and open-circuit voltage loss triggered by high-density interface defects greatly restrict the continuous improvement of Sn-based perovskite solar cells (Sn-PVSCs). Herein, a novel amphoteric semiconductor, O-pivaloylhydroxylammonium trifluoromethanesulfonate (PHAAT), is developed to manage interface defects and carrier dynamics of Sn-PVSCs. The amphiphilic ionic modulators containing multiple Lewis-base functional groups can synergistically passivate anionic and cationic defects while coordinating with uncoordinated Sn to compensate for surface charge and alleviate the Sn oxidation.

Surface-Engineered Ti C T with Tunable Work Functions for Highly Efficient Polymer Solar Cells.

Ti C T , as a newly investigated 2D material, has gained great attention owing to its metallic conductivity, tunable work function (W ), and unique electrical property. However, its W can be further adjusted to meet the needs of optoelectronic devices. Here, surface-engineered Ti C T is fabricated with tunable W by treating with ethanolamine and rhodium chloride (RhCl ).

Several Triazine-Based Small Molecules Assisted in the Preparation of High-Performance and Stable Perovskite Solar Cells by Trap Passivation and Heterojunction Engineering.

The functional group is the main body in modifying the perovskite film, and different functional groups lead to different modification effects. Here, several conjugated triazine-based small molecules such as melamine (Cy-NH), cyanuric acid (Cy-OH), cyanuric fluoride (Cy-F), cyanuric chloride (Cy-Cl), and thiocyanuric acid (Cy-SH) are used to modify perovskite films by mixing in antisolvent. The crystallizations of perovskites are optimized by these molecules, and the perovskite films with low trap density are obtained by forming Lewis adducts with these molecules (Pb and electron-donating groups including -NH, C═N-, and C═O; I and electron-withdrawing groups including F, Cl, N-H, and O-H).

Efficient Ternary Polymer Solar Cells with Tunable Crystallinity and Phase Separation of Active Layers via Incorporating GHK-Cu.

The crystallinity of a nonfullerene small-molecule acceptor plays an important function in the bimolecular recombination and carrier transfer of polymer solar cells (PSCs). However, because of the competition between the donor (PBDB-T) and acceptor (ITIC) in processes of phase separation and crystallization, the PBDB-T preferentially forms a crystalline network, which limits the molecular diffusion of ITIC and leads to the weak crystallinity of ITIC, eventually restricting the photoelectric conversion efficiency (PCE) of PSCs. Therefore, in our work, a small-molecule biomaterial, Gly-His-Lys-Cu (SMBM GHK-Cu), is incorporated into binary PBDB-T:ITIC to construct a PBDB-T:ITIC:GHK-Cu ternary system.

High-efficiency ternary polymer solar cells with optimized morphology of active layers enabled by few-layered β-InSe nanosheets.

Due to the excellent electrical and optical properties, few-layered β-indium selenide (InSe) nanosheets are successfully introduced into the active layer of polymer solar cells (PSCs) as the third component for the first time. The addition of few-layered β-InSe nanosheets optimizes the absorption, crystallinity and vertical component distribution of the active layer. Compared with the binary devices, the ternary devices exhibit optimized bulk morphology and reduced charge recombination.

Solution-Processable PEDOT:PSS:α-InSe with Enhanced Conductivity as a Hole Transport Layer for High-Performance Polymer Solar Cells.

Two-dimensional (2D) nanosheets have attracted significant attention in photovoltaic devices in recent years owing to their outstanding photoelectric properties. Herein, 2D α-InSe nanosheets with high conductivity and suitable work function are synthesized by liquid-phase exfoliation method. To ameliorate the low conductivity of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) (2.

Two-Dimensional BiOSe with High Mobility for High-Performance Polymer Solar Cells.

Carrier mobility is a critical factor for power conversion efficiency (PCE) of polymer solar cells (PSCs), and the low charge carrier mobility still limits the performance improvement of PSCs. Adding high-mobility material into the active layer is one of the better ways to enhance the PCE of PSCs. Two-dimensional (2D) BiOSe can be an ideal additive material for improving the carrier mobility of PSCs because of its ultrahigh mobility and high thermal stability.

Size-tunable near-infrared PbS nanoparticles synthesized from lead carboxylate and sulfur with oleylamine as stabilizer.

High quality PbS nanocrystals are synthesized reproducibly through lead stearate and sulfur stabilized by oleylamine in a non-coordinating solvent. The morphology, crystalline form and phase composition of PbS nanocrystals are examined by transmission electron microscopy (TEM), high-resolution TEM, x-ray diffraction (XRD), energy-dispersive x-ray spectroscopy (EDS) and x-ray photoelectron spectroscopy (XPS). The as-synthesized PbS nanocrystals have strong absorption and photoluminescence emissions in the near-infrared region.