采用532nm锁模激光研究量子阱中的带填充效应

Study of band-filling effect in quantum well with excitation of 532 nm picosecond laser

采用532nm锁模脉冲激光和时间分辨测量系统测量了InGaAs/GaAa单量子阱在77K时,不同激发功率下的时间分辨光致发光谱.结果表明,在低激发功率时,阱中的发光峰的位置随时间变化不大.而在175mW激发时,发光峰在刚激发时就向短波移动10meV以上,然后随时间向长波移动.结果明确显示了存在于阱中的带填充效应.

By using a mode-locked picosecond pulse laser at 532 nm and a time-resolved detection system, we have measured the time-resolved ptotoluminescence spectra of InαGa1-αAs/GaAs single quantum well samples at 77K with different excitation powers. At low excitation, the photoluminescence peak of InGaAs well shows small shift with, the time. But at 175 mW excitation, there is a great blue shift of the photoluminescenoe peak at the beginning and shift back to the longer wavelength side with the time. The result clearly shows the band-filling effect of the carriers exising in the well.