“…The effective Bohr radius is given by,
where a 0 is the Bohr radius of hydrogen, ɛ r is the relative permittivity,
is the electron effective mass, and m e the electron mass. Taking the most reliable known values for bixbyite indium oxide (ε r ≈ 10.55 [
48 ] and
near the bottom of the conduction band [
37,49 ] ) gives an estimated a * of 3.1 nm. It is likely that the permittivity of amorphous indium oxide differs somewhat, but it is unimportant for this example calculation.…”