发光二极管中负电容现象的机理

Mechanism of Negative Capacitance in LEDs

为解释发光二极管(LEDs)中的负电容(NC)现象,提出了在有源区与局部强复合效应有关的新模型,首次通过对载流子连续性方程的求解导出了NC的解析表达式。理论结果表明,在一定的范围内激活区载流子复合速率越大,LEDs中的NC效应越显著,这与实验结果完全一致。它表明,LEDs中的NC是由其激活区载流子复合引起的,而非外部原因造成。

In order to explain the phenomena of negative capacitance（NC） in light-emitting diodes（LEDs） ,we presented a new model based upon the local strong recombination in active region. And we deduced the analytic expression of NO from continuity equation. The theoretical result shows that the NO effect becomes stronger when the carries recombination rate,for a certain range, increases. And it consists with the experimental result. Accordingly,we confirm that the NO is caused by carries recombination in active region instead of by other exterior factors.