The bulk photovoltaic effect(BPVE)refers to the generation of a steady photocurrent and above-bandgap photovoltage in a single-phase homogeneous material lacking inversion symmetry.The mechanism of BPVE is decidedly d...The bulk photovoltaic effect(BPVE)refers to the generation of a steady photocurrent and above-bandgap photovoltage in a single-phase homogeneous material lacking inversion symmetry.The mechanism of BPVE is decidedly different from the typical p-n junction-based photovoltaic mechanism in heterogeneous materials.Recently,there has been renewed interest in ferroelectric materials for solar energy conversion,inspired by the discovery of above-bandgap photovoltages in ferroelectrics,the invention of low bandgap ferroelectric materials and the rapidly improving power conversion efficiency of metal halide perovskites.However,as long as the nature of the BPVE and its dependence on composition and structure remain poorly understood,materials engineering and the realisation of its true potential will be hampered.In this review article,we survey the history,development and recent progress in understanding the mechanisms of BPVE,with a focus on the shift current mechanism,an intrinsic BPVE that is universal to all materials lacking inversion symmetry.In addition to explaining the theory of shift current,materials design opportunities and challenges will be discussed for future applications of the BPVE.展开更多
The manganite La0.67Sr0.33MnO3 （LSMO） thin films were grown on glass substrates in a mixed argon and oxygen atmosphere by using RF magnetron sputtering. The structural characteristics, transport behaviors and magnet...The manganite La0.67Sr0.33MnO3 （LSMO） thin films were grown on glass substrates in a mixed argon and oxygen atmosphere by using RF magnetron sputtering. The structural characteristics, transport behaviors and magnetic properties of LSMO films were studied by annealing the films in air at 550 and 620℃. The out-of-plane lattice parameter αLSMO contracted after annealing and was close to that of bulk LSMO abulk, indicating that the internal strain was fully relaxed. Nanocrystalline grains were observed in the annealed films. Enhanced saturation magnetization and metal-to-insulator transition temperature （TMI=268 K） were also obtained. Curie temperatures （Tc） of the as-grown films was 340 K with the same as that of annealed at 550℃, but dropped to 315 K when the annealing temperature increased to 620℃, which can be attributed to the oxygen release during annealing in atmosphere.展开更多
基金supported by the US Department of Energy(DOE),under grant DE-FG02-07ER46431supported by a National Research Council Research Associateship Award at the US Naval Research Laboratory+1 种基金the support from the Carnegie Institution for Sciencesupport from the NERSC of the DOE.
文摘The bulk photovoltaic effect(BPVE)refers to the generation of a steady photocurrent and above-bandgap photovoltage in a single-phase homogeneous material lacking inversion symmetry.The mechanism of BPVE is decidedly different from the typical p-n junction-based photovoltaic mechanism in heterogeneous materials.Recently,there has been renewed interest in ferroelectric materials for solar energy conversion,inspired by the discovery of above-bandgap photovoltages in ferroelectrics,the invention of low bandgap ferroelectric materials and the rapidly improving power conversion efficiency of metal halide perovskites.However,as long as the nature of the BPVE and its dependence on composition and structure remain poorly understood,materials engineering and the realisation of its true potential will be hampered.In this review article,we survey the history,development and recent progress in understanding the mechanisms of BPVE,with a focus on the shift current mechanism,an intrinsic BPVE that is universal to all materials lacking inversion symmetry.In addition to explaining the theory of shift current,materials design opportunities and challenges will be discussed for future applications of the BPVE.
基金financial support from the National Natural Science Foundation of China (Grants No. 10974118)Shandong Province Natural Science Foundation (ZR2009GQ010)+1 种基金Scientific and Technological Developing Scheme of Shandong Province (Grant No.2008GG30004004)the Independent Innovation Foundation of Shandong University (IIFSDU,2010TS056)
文摘The manganite La0.67Sr0.33MnO3 （LSMO） thin films were grown on glass substrates in a mixed argon and oxygen atmosphere by using RF magnetron sputtering. The structural characteristics, transport behaviors and magnetic properties of LSMO films were studied by annealing the films in air at 550 and 620℃. The out-of-plane lattice parameter αLSMO contracted after annealing and was close to that of bulk LSMO abulk, indicating that the internal strain was fully relaxed. Nanocrystalline grains were observed in the annealed films. Enhanced saturation magnetization and metal-to-insulator transition temperature （TMI=268 K） were also obtained. Curie temperatures （Tc） of the as-grown films was 340 K with the same as that of annealed at 550℃, but dropped to 315 K when the annealing temperature increased to 620℃, which can be attributed to the oxygen release during annealing in atmosphere.
