Band engineering and absorption spectra in compressively strained Ge0.92Sn0.08/Ge (001) double quantum well for infrared photodetection. Issue 11 (8th August 2014)

• Record Type: Journal Article
• Authors: Yahyaoui, N.; Sfina, N.; Lazzari, J.‐L.; Bournel, A.; Said, M.; Pizzini, Sergio; Kissinger, Gudrun
• Is Part Of: Physica status solidi. Volume 11:Issue 11/12(2014)
• Page Start: 1561
• Page End: 1565
• Publication Date: 2014-08-08
• Subjects: Solid state physics -- Congresses; Solid state physics -- Periodicals; Solid state physics; Conference proceedings; Periodicals; 530.41
• DOI: 10.1002/pssc.201400054
• Languages: English
• ISSNs: 1862-6351

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>We report a theoretical investigation of strained Ge_{1−<italic>x</italic>}Sn_{<italic>x</italic>}/Ge (001)‐oriented quantum wells as a bulding block in active region of infrared photodetector. The electronic band parameters, gaps, discontinuities and effective masses for heterointerfaces between compressively strained Ge_{1−<italic>x</italic>}Sn<italic>_{<italic>x</italic>}</italic> and relaxed Ge have beencomputed at room temperature. From this preliminary and mendatory work, we conclude that pseudomorphic Ge_{1−<italic>x</italic>}Sn_{<italic>x</italic>} alloys become direct band gap semiconductors at a Sn‐fraction of 15.3%, e.g. a lattice mismatch as high as 2.3%. Due to achievable critical layer thickness and mainly solid solubility limit, a type‐I compressively strained Ge/Ge_0.92Sn_0.08/Ge (double) quantum well is studied by solving Schrödinger equation without and applied bias voltage. A strong absorption coefficient (&gt; 1×10⁴ cm⁻¹) and a Stark shift of the direct transition between 2.01 μm and 2.25 μm at large external fields (40kV/cm) are attractive characteristics for the design of infrared photodetectors (© 2014 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)</p> </abstract>