We have investigated lateral conduction mid-infrared photodetectors using the photoionization of holes in the valence band of self-assembled Ge/Si quantum dots. A mid-infrared photocurrent signal was observed in the photon energy range of 140-400 meV resulting from an intersubband transition in the valence band of self-assembled Ge quantum dots and subsequent lateral transport of photoexcited carriers in the SiGe conduction channel. The peak responsivity was 134 mA W~(-1) at a photon energy of 240 me V at T = 10 K. Furthermore, the band structure of the Ge QD system was estimated using electrical and optical measurements.
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机译:我们已经研究了使用自组装Ge / Si量子点价带中空穴的光电离的横向传导中红外光电探测器。在自组装的Ge量子点的价带中进行子带间跃迁以及随后在SiGe传导通道中横向激发光激发载流子,在140-400 meV的光子能量范围内观察到了中红外光电流信号。在T = 10 K时,在240 me V的光子能量下,峰值响应率为134 mA W〜(-1)。此外,使用电学和光学测量来估算Ge QD系统的能带结构。
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