【摘要】 用简并激发 -探测技术研究了 77K温度下 In As/Ga As量子点中载流子快速俘获和弛豫过程 .在瞬态反射谱测量中 ,除观察到与 Ga As有关的驰豫过程外 (时间常数约为 lps) ,还观察到一个时间常数为几个至 2 0 ps的反射率上升过程 .提出了一个物理模型 ,表明上述上升过程与光致载流子被 In As层快速俘获过程有关 ,并由此得到载流子的俘获时间 ,俘获时间随载流子浓度增加而减小 .更多还原

【Abstract】 The rapid carrier capture and relaxation processes in InAs/GaAs quantum dots were studied at 77K by using a simple degenerate pump probe technique. A rising process was observed in the transient reflectivity, following the initial fast relaxation associated with GaAs bulk matrix, and this rising process was assigned to be related to the carrier capture from the GaAs barriers to InAs layers. The assignment was modeled using Kramers Kronig relation. By analyzing the rising process observed in the transient reflectivity, the carrier capture time constants were obtained. The measured capture times decrease with the increase of carrier concentration.更多还原