载流子复合机制对不同发光波长InGaN基LED调制带宽的影响

Effect of Carrier Recombination Mechanism on Modulation Bandwidth of InGaN-Based LEDs with Different Emission Wavelengths

传统的ABC模型主要用于研究InGaN量子阱中载流子的复合动态过程。使用传统的ABC模型计算载流子的复合速率和复合寿命,研究不同发光波长InGaN基LED的3 dB调制带宽与载流子复合机制的关系。计算分析结果表明,在相同的注入电流下,随着有效有源区厚度和量子阱层厚度的减小,400 nm近紫外、455 nm蓝光以及525 nm绿光三种发光波长LED的3 dB调制带宽均明显增大;在100 A/cm^(2)的注入电流密度下,400,455,525 nm三种发光波长LED的3 dB调制带宽分别为62,88,376 MHz;在相同的电流密度下,LED的3 dB调制带宽随着In组分(In元素的原子数分数占In元素与Ga元素的原子数分数总和的比)的增加而增大;由于525 nm波长LED的In组分高,有效有源区厚度薄,所以源区载流子浓度高,在大电流密度下525 nm绿光LED的3 dB调制带宽达到376 MHz。

The traditional ABC model is used to study the dynamic recombination process of carriers in InGaN quantum wells.Based on the traditional ABC model,the carrier recombination rate and lifetime are calculated and the relationship between the 3 dB modulation bandwidth of InGaN-based LEDs with different emission wavelengths and the carrier recombination mechanism is studied.The calculation and analysis results show that under the same injection current,with the reduction in the effective active region thickness and quantum well layer thickness,the 3 dB modulation bandwidth of the 400 nm near-ultraviolet,455 nm blue,and 525 nm green light-emitting wavelength of LEDs increases significantly.At the injection current density of 100 A/cm^(2),the 3 dB modulation bandwidth of the 400,455,and 525 nm wavelength LEDs are 62,88,and 376 MHz,respectively.At the same current density,the 3 dB modulation bandwidth of LED increases with the increase of the In composition(the ratio of the atomic number fraction of In element to the sum of the atomic number fraction of In and Ga elements).Moreover,because of the high In composition of the 525 nm wavelength LED,the thickness of effective active region is small and the carrier concentration in the active region is high.Moreover,the 3 dB modulation bandwidth of the 525 nm green LED reaches 376 MHz at high current density.