This article is cited in 8 papers

CONDENSED MATTER

Suppression of hole relaxation in small-sized Ge/Si quantum dots

A. I. Yakimov^ab, V. V. Kirienko^a, A. A. Bloshkin^ac, V. A. Armbrister^a, A. V. Dvurechenskii<sup>ca

a</sup> Rzhanov Institute of Semiconductor Physics SB of the RAS, 630090 Novosibirsk, Russia
^b Tomsk State University, 634050 Tomsk, Russia
^c Novosibirsk State University, 630090 Novosibirsk, Russia

Abstract: We study the effect of quantum dot size on the mid-infrared photocurrent, photoconductive gain, and hole capture probability in ten-period $p$-type Ge/Si quantum dot heterostructures. The dot dimensions is varied by changing the Ge coverage during molecular beam epitaxy of Ge/Si(001) system in the Stranski–Krastanov growth mode while keeping the deposition temperature to be the same. A device with smaller dots is found to exhibit a lower capture probability and a higher photoconductive gain and photoresponse. The integrated responsivity in the mid-wave atmospheric window ($\lambda =(3{-}5)\,\mu$m) is improved by a factor of about $8$ when the average in-plane dot dimension changes from $18$ to $11$ nm. The decrease of the dot size is expected to reduce the carrier relaxation rate due to phonon bottleneck by providing strong zero-dimensional quantum mechanical confinement.

Received: 10.09.2015

Language: English

DOI: 10.7868/S0370274X15210055

 English version: Journal of Experimental and Theoretical Physics Letters, 2015, 102:9, 594–598

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