A novel potassium-containing quadruple-cation absorber realizes over 20% efficiency and hysteresis elimination for planar perovskite solar cells.

Inkjet-printed flexible transparent aesthetic supercapacitors were constructed for the first time using PEDOT:PSS/Ag grids as both current collectors and electrodes.

Two star-shaped helical perylene diimide (PDI) electron acceptors TPDI2 and FTPDI2 were designed and synthesized for nonfullerene organic solar cells (OSCs). The integration of helical PDIs into a three-dimensional structure provides a new strategy to tune the intermolecular interactions, and the as-cast blend films with PTB7-Th show favorable morphology as well as efficient charge transfer and separation, as evidenced by the morphology and femtosecond transient absorption (fs-TA) spectroscopy studies. A trade-off between suppressing the self-aggregation and maintaining the charge-transfer properties was achieved by FTPDI2. Using PTB7-Th as the electron donor, the FTPDI2-based nonfullerene OSCs show a high power conversion efficiency of 8.28%, without the assistance of any additives.

A family of trigonal starburst conjugated molecules (TrFPy, TrFPy, and TrF2Py) composed of a truxene core and pyrene cappers with various bridge lengths is synthesized and characterized. The incorporation of pyrene cappers successfully depress the crystallization tendency, resulting in enhanced glassy temperature and improved morphological stability of the thin films. The high photoluminescence yield in neat films and excellent thermal stability render these pyrene‐capped starbursts promising lasing optical gain media. Low amplified spontaneous emission (ASE) thresholds (EthASE) of 180 nJ pulse‐1 and 101 nJ pulse–1 were recorded for TrFPy and TrF2Py, respectively. One dimensional distributed feedback (1D DFB) lasers demonstrated lasing threshold of 9.3 kW/cm2 and 7.3 kW/cm2 for TrFPy (at 457 nm) and TrF2Py lasers (at 451 nm), respectively. The ASE performance of TrFPy and TrF2Py in an ambient condition was recorded with various annealing temperature (from 80 to 250 °C, 10 min). Surprisingly, TrFPy exhibited excellent ASE stability in an ambient condition, which is still detectable even after annealing at 250 °C for 10 min. The results suggest the pyrene‐capped molecular design strategy is positive on improving the optical gain stability and meanwhile maintaining excellent lasing properties.