Predicted band gap of the new semiconductor SiGeSn

Abstract

The direct and indirect band gaps of Si1−x−yGexSny are inferred from the calculated energy-band structure of α-Sn and from the known structures of Ge and Si. Our assumptions are: that the energy-band shapes of the binaries Sn1−xGex, Ge1−ySiy and Si1−ySny change smoothly with x and y, and that the energy gap of SiGeSn can be estimated by interpolation from the gaps of SnGe, GeSi, and SiSn. The optical indices of refraction of SiGeSn are also estimated.

Strain-free Ge∕GeSiSn quantum cascade lasers based on L-valley intersubband transitions

“…Ge 1−x−y Si x Sn y alloys have been studied for the possibility of forming direct band gap semiconductors. [6][7][8][9] Since the initial growth of this alloy, 10 device-quality epilayers with a wide range of alloy contents have been achieved. Incorporation of Sn provides the opportunity to engineer separately the strain and band structure since we can vary the Si ͑x͒ and Sn ͑y͒ compositions independently.…”

Endotaxial Growth Mechanisms of Sn Quantum Dots in Si Matrix

“…After this time, the function <r> 3 (t) showed the typical linear behavior that is expected for precipitate coarsening by volume diffusion [14]. Non-linearities of <r> 3 with time are commonly attributed to diffusion shortcuts such as dislocations, stacking faults, grain boundaries, and other common lattice defects [14].…”

“…Earlier plan view TEM investigations of Sn x Si 1-x layers annealed at 650 ºC at the California Institute of Technology revealed an initially rapid increase of the average QD volume (<r> 3 ) with time (t) for the first 2.2 hours of the anneal, Fig. 1a, [9].…”

“…As α-Sn is a direct, 0.08 eV, band gap semiconductor and substitutional Sn x Si 1-x solution are predicted to possess direct band gaps for 0.9 < x < 1 [3], QDs in a Si matrix consisting of pure α-Sn or substitutional (Sn,Si) solutions with a sufficiently high Sn content have potential applications as direct band-gap material for cheap and effective optoelectronic and thermo-photovoltaic devices. There are, however, at room temperature a 41.8 % bulk unit cell volume mismatch between α-Sn and Si and an equilibrium solid solubility of Sn in Si of only 0.12 %.…”

Band gap engineering of Si-Ge alloys for mid-temperature thermoelectric applications

“…[29][30][31][32][33][34] To study the effects of Sn substitutions in Si-Ge alloys (Si 0.50 Ge 0.125 Sn 0.375 ), we compute the properties of Si 0.75 Ge 0.25 -a near composition that had been extensively used in thermoelectric applications, with its thermoelectric figure-of-merit (ZT) being 1.3 and 0.95 for n and p type, respectively. 35,36 For the fully relaxed structure, the equilibrium lattice constant (bulk modulus) were determined as 5.536 Å (80.5 GPa) and 5.899 Å (52.1 GPa) for Si 0.75 Ge 0.25 and Si 0.50 Ge 0.125 Sn 0.375 , respectively.…”