The two-band model predicts that is roughly constant across direct-gap III-V…

PHYSICS · Multi-part · Fermi University Physics · Condensed Matter, Materials & Soft Matter · Free electrons, energy bands and electronic structure · Semiconductor physics and devices

Solid State Physics, Ch Semiconductors: masses, statistics, defect levels and mobility

Problem

The two-band k⋅p\mathbf{k}\cdot\mathbf{p} model predicts that m∗/Egm^*/E_g is roughly constant across direct-gap III-V semiconductors with the conduction minimum at Γ\Gamma: across InSb, InAs, GaSb, InP and GaAs (with EgE_g ranging from 0.170.17 to 1.42 eV1.42\,\mathrm{eV}) the ratio lies between 0.0470.047 and 0.082 eV−10.082\,\mathrm{eV^{-1}}. The ternary alloy In0.53_{0.53}Ga0.47_{0.47}As is a direct-gap semiconductor with its conduction minimum at Γ\Gamma and Eg=0.75 eVE_g=0.75\,\mathrm{eV} at 300 K300\,\mathrm{K}. ((a)) Use the quoted range of m∗/Egm^*/E_g to bracket the electron effective mass of In0.53_{0.53}Ga0.47_{0.47}As. ((b)) The measured value is m∗=0.041 mem^*=0.041\,m_e. State whether it falls inside the estimated bracket.

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