Experimental study of negative capacitance in LEDs

Abstract:

The experimental study on negative capacitance (NC) of various light-emitting diodes (LEDs) is presented. Experimental result shows that all LEDs display the NC phenomenon. The voltage modulated electroluminescence (VMEL) experiment confirms that the reason of negative capacitance is the strong recombination of the injected carriers in the active region of luminescence. The measures also verify that the dependence of NC on voltage and frequency in different LEDs is similar; NC phenomenon is more obvious with higher voltage or lower frequency.