Loading...

Origin of apparent light-enhanced and negative capacitance in perovskite solar cells

Ebadi, F ; Sharif University of Technology | 2019

789 Viewed
  1. Type of Document: Article
  2. DOI: 10.1038/s41467-019-09079-z
  3. Publisher: Nature Publishing Group , 2019
  4. Abstract:
  5. So-called negative capacitance seems to remain an obscure feature in the analysis of the frequency-dependent impedance of perovskite solar cells. It belongs to one of the puzzling peculiarities arising from the mixed ionic-electronic conductivity of this class of semiconductor. Here we show that apparently high capacitances in general (positive and negative) are not related to any capacitive feature in the sense of a corresponding charge accumulation. Instead, they are a natural consequence of slow transients mainly in forward current of the diode upon ion displacement when changing voltage. The transient current leads to a positive or negative ‘capacitance’ dependent on the sign of its gradient. The ‘capacitance’ appears so large because the associated resistance, when thinking of a resistor-capacitor element, results from another physical process, namely modified electronic charge injection and transport. Observable for a variety of devices, it is a rather universal phenomenon related to the hysteresis in the current–voltage curve. © 2019, The Author(s)
  6. Keywords:
  7. Fluorine doped tin oxide ; Mesoporous titanium dioxide nanoparticle ; Perovskite ; Unclassified drug ; Electric field ; Electrical conductivity ; Electrical resistivity ; Fuel cell ; Light effect ; Perovskite ; Article ; Electric capacitance ; Electric potential ; Electrochemical analysis ; Energy dispersive X ray spectroscopy ; Fluorescence resonance energy transfer ; Hysteresis ; Impedance ; Impedance spectroscopy ; Infrared spectroscopy ; Nonhuman ; Refraction index ; Scanning electron microscopy ; Temperature ; X ray diffraction
  8. Source: Nature Communications ; Volume 10, Issue 1 , 2019 ; 20411723 (ISSN)
  9. URL: https://www.nature.com/articles/s41467-019-09079-z