Photoelectric Properties of InAs/GaAs Quantum Dot Photoconductive Antenna Wafers
Photoelectric Properties of InAs/GaAs Quantum Dot Photoconductive Antenna Wafers
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DOI：
10.1109/jstqe.2017.2690831
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发表时间：
2018-03
影响因子：
4.9
通讯作者：
Andrei Gorodetsky;A. Yadav;E. Avrutin;K. Fedorova;E. Rafailov
中科院分区：
文献类型：
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作者：
Andrei Gorodetsky;A. Yadav;E. Avrutin;K. Fedorova;E. Rafailov
本文报道了自组装 InAs/GaAs 量子点光电导天线在 1140 nm 至 1250 nm 波长范围内、13 至 400 K 温度范围内的光电导性研究。这些天线旨在与量子点半导体激光器配合工作，以有效地产生脉冲和连续波太赫兹辐射。为了有效运行，应确定提供最高光电流的激光波长。为了研究量子点光电导天线在室温和低温下的带间光电导性，我们采用了宽可调的 InAs/GaAs 量子点激光器，提供在 100 nm 可调谐范围内功率超过 20 mW 的相干泵浦。量子点天线结构在波长附近显示出尖锐的温度依赖性光电导峰，对应于 InAs/GaAs 量子点的基态和激发态。基态光电导峰随着温度下降而消失，而激发态峰仍然存在。我们将这种效应与从量子点提取光激发载流子的不同机制联系起来。
In this paper, the study of the photoconductivity in self-assembled InAs/GaAs quantum dot photoconductive antenna in the wavelength region between 1140 nm and 1250 nm at temperatures ranging from 13 to 400 K is reported. These antennas are aimed to work in conjunction with quantum dot semiconductor lasers to effectively generate pulsed and continuous wave terahertz radiation. For the efficient operation, laser wavelengths providing the highest photocurrent should be determined. To study the interband photoconductivity of quantum dot photoconductive antennas, at room and cryogenic temperatures, we employed a broadly-tunable InAs/GaAs quantum dot based laser providing a coherent pump with power exceeding 20 mW over a 100 nm tunability range. The quantum dot antenna structure revealed sharp temperature-dependent photoconductivity peaks in the vicinity of wavelengths, corresponding to the ground and excited states of InAs/GaAs quantum dots. The ground state photoconductivity peak vanishes with a temperature drop, whereas the excited state peak persists. We associate this effect with different mechanisms of photoexcited carriers extraction from quantum dots.