Quantifying the conductivity of a single polyene chain by lifting with an STM tip.

Conjugated polymers are promising candidates for molecular wires in nanoelectronics, with flexibility in mechanics, stability in chemistry and variety in electrical conductivity. Polyene, as a segment of polyacetylene, is a typical conjugated polymer with straightforward structure and wide-range adjustable conductance. To obtain atomic scale understanding of charge transfer in polyene, we have measured the conductance of a single polyene-based molecular chain via lifting it up with scanning tunneling microscopy tip.

Efficient Perovskite Solar Cells Based on Tin Oxide Nanocrystals with Difunctional Modification.

Tin oxide (SnO ) nanocrystals-based electron transport layer (ETL) has been widely used in perovskite solar cells due to its high charge mobility and suitable energy band alignment with perovskite, but the high surface trap density of SnO nanocrystals harms the electron transfer and collection within device. Here, an effective method to achieve a low trap density and high electron mobility ETL based on SnO nanocrystals by devising a difunctional additive of potassium trifluoroacetate (KTFA) is proposed. KTFA is added to the SnO nanocrystals solution, in which trifluoroacetate ions could effectively passivate the oxygen vacancies (O ) in SnO nanocrystals through binding of TFA and Sn , thus reducing the traps of SnO nanocrystals to boost the electrons collection in the solar cell.

Multiple-Function Surface Engineering of SnO Nanoparticles to Achieve Efficient Perovskite Solar Cells.

The mismatched energy-level alignment and interface defects of the SnO nanoparticles' electron transport layer (ETL) and perovskite layer worsen the efficiency of the perovskite solar cell. Herein, we devise a multiple-function surface engineering of SnO nanoparticles. TBA ions improve the dispersion and stability of colloidal T-SnO nanoparticles and act as a bridge between the ETL and perovskite layer through the electrostatic interaction with anions, thus suppressing the charge recombination and reducing the energy loss.

Constructing and Transferring Two-Dimensional Tessellation Kagome Lattices via Chemical Reactions on Cu(111) Surface.

Two-dimensional (2D) tessellation of organic species acquired increased interests recently because of their potential applications in physics, biology, and chemistry. 2D tessellations have been successfully constructed on surfaces via various intermolecular interactions. However, the transformation between 2D tessellation lattices has been rarely reported.

Gradient-Band Alignment Homojunction Perovskite Quantum Dot Solar Cells.

The inorganic perovskite CsPbI that exists in the form of a quantum dot (QD) shows a stable cubic structure, attracting much attention for its application in solar cells. However, too many grain boundaries in the perovskite QD (PQD) layer block the transport of carriers, resulting in the potential loss of solar cells. Herein, we devise a gradient-band alignment (GBA) homojunction, which is constructed from three layers of PQDs with different band-gaps to form a gradient energy alignment.