Strained donor-bound excitons in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mi>Si</mml:mi> <mml:mprescripts/> <mml:none/> <mml:mn>28</mml:mn> </mml:mmultiscripts> </mml:math>

We present a comprehensive experimental study of the neutral donor to donor-bound exciton transition ( <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"> <a:mrow> <a:msup> <a:mrow> <a:mi mathvariant="normal">D</a:mi> </a:mrow> <a:mn>0</a:mn> </a:msup> <a:mo>→</a:mo> <a:mspace width="0.16em"/> <a:msup> <a:mrow> <a:mi mathvariant="normal">D</a:mi> </a:mrow> <a:mn>0</a:mn> </a:msup> <a:mi mathvariant="normal">X</a:mi> </a:mrow> </a:math> ) in isotopically enriched <f:math xmlns:f="http://www.w3.org/1998/Math/MathML"> <f:mmultiscripts> <f:mi>Si</f:mi> <f:mprescripts/> <f:none/> <f:mn>28</f:mn> </f:mmultiscripts> </f:math> , focusing on the group V donors P, As, and Sb under finely tuned uniaxial stress along the [100] and [110] crystal axes and magnetic fields from 3.5 mT to 1.7 T. From these measurements, donor-specific deformation potentials are extracted. The uniaxial electron deformation potential <g:math xmlns:g="http://www.w3.org/1998/Math/MathML"> <g:msub> <g:mi mathvariant="normal">Ξ</g:mi> <g:mi mathvariant="normal">u</g:mi> </g:msub> </g:math> is found to be significantly larger than values reported for other states or transitions in silicon and shows clear dependence on the donor species, indicating an increased sensitivity of the <j:math xmlns:j="http://www.w3.org/1998/Math/MathML"> <j:mrow> <j:msup> <j:mrow> <j:mi mathvariant="normal">D</j:mi> </j:mrow> <j:mn>0</j:mn> </j:msup> <j:mi mathvariant="normal">X</j:mi> </j:mrow> </j:math> state to strain and central-cell effects. We also observe a magnetic field dependence of the hole shear deformation potential <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"> <m:mi>d</m:mi> </m:math> , suggesting a more complex strain coupling mechanism than captured by standard theory. Diamagnetic shift parameters determined from Zeeman spectra show good agreement with earlier measurements. Our results provide a refined parameter set critical for the design of silicon quantum devices based on <n:math xmlns:n="http://www.w3.org/1998/Math/MathML"> <n:mrow> <n:msup> <n:mrow> <n:mi mathvariant="normal">D</n:mi> </n:mrow> <n:mn>0</n:mn> </n:msup> <n:mi mathvariant="normal">X</n:mi> </n:mrow> </n:math> transitions.