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
Relaxors exhibit unique dielectric response properties such as diffuse phase transitions and strong dispersion of the dielectric constant.The origin of these properties is still not fully understood.Here,we review our...Relaxors exhibit unique dielectric response properties such as diffuse phase transitions and strong dispersion of the dielectric constant.The origin of these properties is still not fully understood.Here,we review our work on usingfirst-principles-based methods to elucidate the connections between composition,local structure and dynamics in Pb-based relaxors.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This work was supported by the O±ce of Naval Research,under Grant No.N00014-11-1-0578by the NSF under grant DMR11-20901.Computational support was provided by a Challenge Grant from the HPCMO of the U.S.Department of Defense.
文摘Relaxors exhibit unique dielectric response properties such as diffuse phase transitions and strong dispersion of the dielectric constant.The origin of these properties is still not fully understood.Here,we review our work on usingfirst-principles-based methods to elucidate the connections between composition,local structure and dynamics in Pb-based relaxors.
