Quantum heterostructures, related devices and methods for manufacturing the same

A method for preparing a quantum heterostructure, comprising:

• conditioning a reactor chamber to reach initial growth conditions;
• supplying a Ge-based precursor and a Sn-based precursor in the reactor chamber;
• forming a stack of coextending GeSn buffer layers on a substrate comprising a strain-engineered material and provided inside the reactor chamber, comprising:
• forming a first GeSn buffer layer by exposing the substrate to the initial growth conditions;
• conditioning the reactor chamber to reach subsequent growth conditions, comprising:
• changing a reactor temperature;
• and
• varying a molar fraction of at least one of the Sn-based precursor and the Ge-based precursor;
• forming one or more subsequent GeSn buffer layers on the first buffer layer by exposing the first GeSn buffer layer to the subsequent growth conditions, each GeSn buffer layer having a different Sn content from one another, wherein the Sn content of each GeSn buffer layer is comprised in a range extending from 4.9 at. % to 13.4 at. %;
• and
• forming a quantum well over the stack of coextending GeSn buffer layers, the quantum well comprising a highly tensile-strained layer, the highly tensile-strained layer comprising at least one group IV element and having a strain greater than or equal to 1%, wherein the highly tensile-strained layer has a thickness equal or below 10 nm.

A quantum heterostructure, comprising:

• a plurality of buffer layers on a substrate comprising a strain-engineered material, each buffer layer being made from an alloy and having a different composition one from another, the alloy comprising at least two group-IV elements wherein the Sn content of each buffer layer is comprised in a range extending from 4.9 at. % to 13.4 at. %;
• a bottom barrier layer extending over the plurality of buffer layers;
• a tensile-strained semiconductor layer extending over the bottom barrier layer, the tensile-strained semiconductor layer being made from one group-IV element and having a strain greater than or equal to 1%, wherein the highly tensile-strained layer has a thickness equal or below 10 nm;
• and
• a top barrier layer extending over the tensile-strained semiconductor layer.