自组织生长InAs量子点的发光性质研究

Optical Properties of Self-organized InAs Quantum Dots

通过对加InGaAs覆盖层的InAs自组织生长量子点的变温光致发光谱以及时间分辨谱的研究,发现低温下量子点的发光强度和光生载流子的寿命不变;中间温度区载流子寿命随温度升高而变大;更高温度时,发光强度和载流子寿命均随温度升高而快速下降.

Optical properties of InAs/GaAs selforganized quantum dots(QDs) structures have been investigated by the temperaturedependent photoluminescence(PL) and timeresolved photoluminescence(TRPL) spectroscopies. It is found that the quantum dots have the intermediate behavior between the twodimensional and zerodimensional. That is, at low temperatures (<40 K), the PL intensities as well as the carrier lifetimes are independent of the temperature. At the middle temperature region (40～160 K), the carrier lifetime increases with increasing temperature ; simultaneously, the PL peaking energy quickly redshifts with increasing temperature, which is caused by the carriers captured and relaxed within the QDs and between the QDs and the wetting layer(WL) and(or) the GaAs barrier layer. At higher temperatures (>160 K), the electronphonon scattering becomes dominative and the PL intensities and the carrier lifetimes quench quickly with the temperature.