GaAs/AlGaAs多量子阱中载流子动力学的实验研究

Spatiotemporal dynamics of photogenerated carriers in GaAs/AlGaAs multiple quantum wells

利用瞬态光栅激光光谱技术测量了(110)方向生长的本征GaAs/AlGaAs多量子阱的双极扩散系数.室温下,光激发的载流子浓度nex=3.4×1010/cm2时,测得双极扩散系数Da=13.0cm2/s,载流子的寿命τR=1.9ns.改变光激发的载流子浓度(nex≤1.2×1011/cm2)测量,发现双极扩散系数不随着载流子浓度的增加而变化.

The ambipolar diffusion coefficient of （110） GaAs/AlGaAs multiple quantum wells was measured by the transient spin grating technique. The ambipolar diffusion coefficient and carrier life time,which are Da = 13. 0 cm2 /s and τR = 1. 9 ns,were obtained directly by this technique under carrier concentration nex = 3. 4 × 1010 /cm2 at room temperature. The measured Da keeps almost a constant value when the photoexcited carrier concentration is increased up to 1. 2 × 1011 /cm2.