Large-crystal perovskite films: The performance of organic-inorganic hybrid perovskite planar solar cells has steadily improved. One outstanding issue is that grain boundaries and defects in polycrystalline films degrade their output. Now, two studies report the growth of millimeter-scale single crystals. Nie et al. grew continuous, pinhole-free, thin iodochloride films with a hot-casting technique and report device efficiencies of 18%. Shi et al. used antisolvent vapor-assisted crystallization to grow millimeter-scale bromide and iodide cubic crystals with charge-carrier diffusion lengths exceeding 10 mm. Science , this issue p. 522 , p. 519

We employed a binary spacer of orderly conjugated 3,4-ethyldioxythiophene and thienothiophene to construct a wide-spectral response organic chromophore for dye-sensitized solar cells, exhibiting a high power conversion efficiency of 9.8% measured under irradiation of 100 mW cm⁻² air mass 1.5 global (AM1.5G) sunlight and an excellent stability.

A heteroleptic polypyridyl ruthenium complex, cis-Ru(4,4′-bis(5-octylthieno[3,2-b]thiophen-2-yl)-2,2′-bipyridine)(4,4′-dicarboxyl-2,2′-bipyridine)(NCS)₂ , with a high molar extinction coefficient of 20.5 × 10³ M⁻¹ cm⁻¹ at 553 nm has been synthesized and demonstrated as a highly efficient sensitizer for a dye-sensitized solar cell, giving a power conversion efficiency of 10.53% measured under an irradiation of air mass 1.5 global (AM 1.5G) full sunlight.