CP29, one of the minor light-harvesting complexes of higher-plant photosystem II, absorbs and transfers solar energy for photosynthesis and also has important roles in photoprotection. We have solved the crystal structure of spinach CP29 at 2.80-Å resolution. Each CP29 monomer contains 13 chlorophyll and 3 carotenoid molecules, which differs considerably from the major light-harvesting complex LHCII and the previously proposed CP29 model. The 13 chlorophyll-binding sites are assigned as eight chlorophyll a sites, four chlorophyll b and one putative mixed site occupied by both chlorophylls a and b. Based on the present X-ray structure, an integrated pigment network in CP29 is constructed. Two special clusters of pigment molecules, namely a615-a611-a612-Lut and Vio(Zea)-a603-a609, have been identified and might function as potential energy-quenching centers and as the exit or entrance in energy-transfer pathways.

Triple‐cation mixed‐halide perovskites of composition Csx(FAyMA1−y)1−xPb(IzBr1−z)3 (CsFAMA) have been reported to possess excellent photovoltaic efficiency with minimal hysteresis; in this work, nanoscale insight is shed into the roles of illumination‐induced polarization and ionic migration in photovoltaic hysteresis. By examining the concurrent evolution of ionic distribution and spontaneous polarization of CsFAMA under light illumination using dynamic‐strain‐based scanning probe microscopy, strong linear piezoelectricity arising from photoenhanced polarization is observed, while ionic migration is found to be not significantly increased by lightening. Nanoscale photocurrents are mapped under a series of biases using conductive atomic force microscopy, revealing negligible difference between forward and backward scans, and local IV curves reconstructed from principal component analysis show minimal hysteresis of just 1%. These observations at the nanoscale are confirmed in a macroscopic perovskite solar cell made of CsFAMA, exhibiting a high efficiency of 20.11% and with hysteresis index as small as 3%. Ionic migration, polarization, and photocurrent hysteresis are thus directly correlated at the nanoscale, and photoenhanced polarization in triple‐cation mixed‐halide perovskites is established, which does not contribute to the photovoltaic hysteresis.