摘要

Unlike common photovoltaic (PV) cells whose performance has been anchored, the merits for the cells made of ferroelectric crystals, due to the non-centrosymmetric structure, provide possibility to further enhance the efficiency by dual external manipulations through increasing the internal electric field strength and the dielectric screening effect, based on anomalous photovoltaic (APV) arisen by the external poling and giant dielectric constant variation through temperature-controlled ferro-paraelectric phase transition. In this study, a synergistic effect achieving a 67% improvement in power conversion efficiency (PCE) of the n-i-p configuration solar cell by ferroelectric polarization and high dielectricity is observed, taking c-axis-aligned single-crystalline ferroelectric SbSI nanorods as the active layer. The opposite poling effects are revealed leading to asymmetric characteristics in the n-i-p configuration. The enhancements of Jsc induced by inherent giant epsilon SbSI$\left(\epsilon\right)_{\text{SbSI}}$ variation imply strong dielectric screening facilities to lower carrier cross section captured by charged defects, uniformly suppressing various recombination mechanisms, understood by the Langevin model. Therefore, solar cells employing n-i-p structured ferroelectric thin films as absorbing layers hold promising potential for achieving defect-tolerance high performance through rational design, external polarization, and dielectric property control. @@@ A n-i-p structure solar cell with embedded c-axis-aligned single-crystalline ferroelectric SbSI nanorods as the active layer. The power conversion efficiency (PCE) increases from 2.18% (virgin state) to 3.63% (polarized and high dielectric state), 1.67-fold by superimposing ferroelectric polarization and strong dielectricity, manifesting the defect-tolerance characterisic.

  • 单位
    桂林理工大学

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