The amount of doping to make a semiconductor extrinsic depends on the intrinsic carrier density at a particular temperature. The impurity scattering in the presence of doping determines the maximum mobility exhibited by the semiconductor. In the present work, we estimate the values of intrinsic carrier density of the alloy Ge_1−xSn_x for 0 < x < 0.2 at and around 300 K. Since the alloy exhibits a direct-gap nature at x ≥ 0.08, the electron mobility is enhanced due to low effective mass in the lower Γ valley and reduced non-equivalent intervalley scattering. The electron mobility, calculated by considering all scattering processes, increases with increasing x, attains a peak and then decreases. The peak mobility is as high as 10⁵ cm²/V s for donor density equaling intrinsic density. With a 50-fold increase in donor density, the mobility is 3 × 10³ cm²/V s, which is still higher than the value in similarly doped bulk Ge.

使半导体非本征掺杂的量取决于特定温度下的本征载流子密度。在掺杂存在下的杂质散射决定了半导体表现出的最大迁移率。在目前的工作中，我们估计合金的Ge的本征载流子密度的值_{1- X} Sn的_X为0 <  X  <0.2处和周围300 K.由于合金表现出直接的间隙本质X  ≥0.08，电子由于较低的Γ谷中的有效质量较低，并且非等价的区间利散射减少，迁移率得以提高。通过考虑所有散射过程计算出的电子迁移率随x的增加而增加，先达到峰值，然后降低。供体密度等于固有密度的峰值迁移率高达10 ⁵ cm ² / V s。随着施主密度增加50倍，迁移率达到3×10 ³ cm ² / V s，仍高于相似掺杂的块状Ge中的迁移率。