@article{shu_ke_fei_huang_wang_gong_jiang_wang_li_lei_et al._2020, title={Photoflexoelectric effect in halide perovskites}, volume={19}, ISSN={["1476-4660"]}, DOI={10.1038/s41563-020-0659-y}, abstractNote={Harvesting environmental energy to generate electricity is a key scientific and technological endeavour of our time. Photovoltaic conversion and electromechanical transduction are two common energy-harvesting mechanisms based on, respectively, semiconducting junctions and piezoelectric insulators. However, the different material families on which these transduction phenomena are based complicate their integration into single devices. Here we demonstrate that halide perovskites, a family of highly efficient photovoltaic materials1–3, display a photoflexoelectric effect whereby, under a combination of illumination and oscillation driven by a piezoelectric actuator, they generate orders of magnitude higher flexoelectricity than in the dark. We also show that photoflexoelectricity is not exclusive to halides but a general property of semiconductors that potentially enables simultaneous electromechanical and photovoltaic transduction and harvesting in unison from multiple energy inputs. Flexoelectricity is the ability of materials to generate electricity upon bending. Here it is demonstrated that adding light to mechanical oscillation enhances effective flexoelectric coefficients by orders of magnitude, with the halide perovskites showing the largest coefficients.}, number={6}, journal={NATURE MATERIALS}, author={Shu, Longlong and Ke, Shanming and Fei, Linfeng and Huang, Wenbin and Wang, Zhiguo and Gong, Jinhui and Jiang, Xiaoning and Wang, Li and Li, Fei and Lei, Shuijin and et al.}, year={2020}, month={Jun}, pages={605-+} }
 @article{huang_shu_kwon_zhang_yuan_jiang_2014, title={Fabrication and measurement of a flexoelectric micro-pyramid composite}, volume={4}, ISSN={["2158-3226"]}, DOI={10.1063/1.4904024}, abstractNote={A fabrication method by combining precision mechanical dicing and wet etching was developed to prepare micro-pyramid structures based on (Ba0.67Sr0.33)TiO3 ceramics. The effective piezoelectric properties of flexoelectric pyramid structures in ten micrometers scale were investigated and measured through converse flexoelectric effect. The scaling effect of the flexoelectric response was demonstrated as the structure size shrinks down. The results do suggest the great potential of flexoelectric micro pyramids as an alternative to lead-free piezoelectric material.}, number={12}, journal={AIP ADVANCES}, author={Huang, Wenbin and Shu, Longlong and Kwon, Seol Ryung and Zhang, Shujun and Yuan, Fuh-Gwo and Jiang, Xiaoning}, year={2014}, month={Dec} }
 @article{kwon_huang_shu_yuan_maria_jiang_2014, title={Flexoelectricity in barium strontium titanate thin film}, volume={105}, ISSN={["1077-3118"]}, DOI={10.1063/1.4898139}, abstractNote={Flexoelectricity, the linear coupling between the strain gradient and the induced electric polarization, has been intensively studied as an alternative to piezoelectricity. Especially, it is of interest to develop flexoelectric devices on micro/nano scales due to the inherent scaling effect of flexoelectric effect. Ba0.7Sr0.3TiO3 thin film with a thickness of 130 nm was fabricated on a silicon wafer using a RF magnetron sputtering process. The flexoelectric coefficients of the prepared thin films were determined experimentally. It was revealed that the thin films possessed a transverse flexoelectric coefficient of 24.5 μC/m at Curie temperature (∼28 °C) and 17.44 μC/m at 41 °C. The measured flexoelectric coefficients are comparable to that of bulk BST ceramics, which are reported to be 10–100 μC/m. This result suggests that the flexoelectric thin film structures can be effectively used for micro/nano-sensing devices.}, number={14}, journal={APPLIED PHYSICS LETTERS}, author={Kwon, Seol Ryung and Huang, Wenbin and Shu, Longlong and Yuan, Fuh-Gwo and Maria, Jon-Paul and Jiang, Xiaoning}, year={2014}, month={Oct} }
 @article{li_shu_huang_jiang_wang_2014, title={Giant flexoelectricity in Ba0.6Sr0.4TiO3/Ni0.8Zn0.2Fe2O4 composite}, volume={105}, ISSN={["1077-3118"]}, DOI={10.1063/1.4899060}, abstractNote={Enhanced flexoelectricity in perovskite ceramics and single crystals has been reported before. In this letter, 3-3 ceramic-ceramic Ba0.6Sr0.4TiO3/Ni0.8Zn0.2Fe2O4 composite with a colossal permittivity was employed in the conventional pure bending experiment in order to examine the transverse flexoelectric response. The measured flexoelectric coefficient at 30 Hz is 128 μC/m and varies to 16 μC/m with the frequency increasing from 30 Hz to 120 Hz, mainly due to the inverse correlation between the permittivity and the frequency. This result reveals the permittivity dependence of flexoelectric coefficient in the frequency dispersion materials, suggesting that the giant permittivity composites can be good flexoelectric materials.}, number={16}, journal={APPLIED PHYSICS LETTERS}, author={Li, Yong and Shu, Longlong and Huang, Wenbin and Jiang, Xiaoning and Wang, Hong}, year={2014}, month={Oct} }
 @article{shu_li_huang_wei_yao_jiang_2014, title={Relationship between direct and converse flexoelectric coefficients}, volume={116}, ISSN={["1089-7550"]}, DOI={10.1063/1.4897647}, abstractNote={Flexoelectric effect, as a universal electromechanical coupling, has drawn lots of interests in dielectric materials. However, due to the restrictions of present measurement techniques, only part of coefficients has been experimentally examined. In this study, we derived the coordinate-dependent Gibbs free energy density function in the inhomogeneous spatial field to investigate the relationship between the direct and converse flexoelectric coefficients. In crystalline mediums and systems, the direct and converse flexoelectric coefficients are proved to equivalent according to the Maxwell relation. These results will broaden the application of the Maxwell relation into non-linear spatial field, and provide the guideline for experimental measurement and prediction of flexoelectric coefficients.}, number={14}, journal={JOURNAL OF APPLIED PHYSICS}, author={Shu, Longlong and Li, Fei and Huang, Wenbin and Wei, Xiaoyong and Yao, Xi and Jiang, Xiaoning}, year={2014}, month={Oct} }