Hydrostatic-pressure dependence of band offsets in GaAs/AlxGa1-xAs heterostructures.
Hydrostatic-pressure dependence of band offsets in GaAs/AlxGa1-xAs heterostructures.
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GaAs/AlxGa1-xAs 异质结构中能带偏移的静水压力依赖性。
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
Gossard
中科院分区：
文献类型：
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作者：
Cheong;Burnett;Paul;Hopkins;Gossard
We have determined the pressure dependences of the band offsets in the GaAs/${mathrm{Al}}_{mathit{x}}$${mathrm{Ga}}_{1mathrm{ensuremath{-}}mathit{x}}$As heterojunctions by measuring the pressure dependences of the harmonic-oscillator-like electron-energy-level spacings ensuremath{Elzxh}${mathrm{ensuremath{omega}}}_{mathit{e}}$ of two ${mathrm{Al}}_{mathit{x}}$${mathrm{Ga}}_{1mathrm{ensuremath{-}}mathit{x}}$As parabolic quantum wells at hydrostatic pressures up to ensuremath{sim}26 kbar at 2 K using photoluminescence-excitation spectroscopy. We found that the conduction-band offset for xensuremath{approxeq}0.3 increases with pressure at a rate of 0.73ifmmodepmelse extpmfi{}0.25 meV/kbar. Using this result and the finding that the pressure coefficient of the direct-band-gap energy of ${mathrm{Al}}_{mathit{x}}$${mathrm{Ga}}_{1mathrm{ensuremath{-}}mathit{x}}$As is independent of x for x=0-0.4, we found that the fractional conduction- (valence-) band offset ${mathit{Q}}_{mathit{c}}$ (${mathit{Q}}_{mathit{v}}$) of GaAs/${mathrm{Al}}_{mathit{x}}$${mathrm{Ga}}_{1mathrm{ensuremath{-}}mathit{x}}$As increases (decreases) with pressure at a rate of 0.0020ifmmodepmelse extpmfi{}0.0007 ${mathrm{kbar}}^{mathrm{ensuremath{-}}1}$. From this result, we conclude that the previous determinations of the band-offset values of GaAs/${mathrm{Al}}_{mathit{x}}$${mathrm{Ga}}_{1mathrm{ensuremath{-}}mathit{x}}$As by high-pressure measurements overestimated (underestimated) the fractional conduction- (valence-) band offset by 0.06ifmmodepmelse extpmfi{}0.02, and the corrected ${mathit{Q}}_{mathit{c}}$ value at atmospheric pressure should be 0.63ifmmodepmelse extpmfi{}0.04.
We have determined the pressure dependences of the band offsets in the GaAs/${mathrm{Al}}_{mathit{x}}$${mathrm{Ga}}_{1mathrm{ensuremath{-}}mathit{x}}$As heterojunctions by measuring the pressure dependences of the harmonic-oscillator-like electron-energy-level spacings ensuremath{Elzxh}${mathrm{ensuremath{omega}}}_{mathit{e}}$ of two ${mathrm{Al}}_{mathit{x}}$${mathrm{Ga}}_{1mathrm{ensuremath{-}}mathit{x}}$As parabolic quantum wells at hydrostatic pressures up to ensuremath{sim}26 kbar at 2 K using photoluminescence-excitation spectroscopy. We found that the conduction-band offset for xensuremath{approxeq}0.3 increases with pressure at a rate of 0.73ifmmodepmelse extpmfi{}0.25 meV/kbar. Using this result and the finding that the pressure coefficient of the direct-band-gap energy of ${mathrm{Al}}_{mathit{x}}$${mathrm{Ga}}_{1mathrm{ensuremath{-}}mathit{x}}$As is independent of x for x=0-0.4, we found that the fractional conduction- (valence-) band offset ${mathit{Q}}_{mathit{c}}$ (${mathit{Q}}_{mathit{v}}$) of GaAs/${mathrm{Al}}_{mathit{x}}$${mathrm{Ga}}_{1mathrm{ensuremath{-}}mathit{x}}$As increases (decreases) with pressure at a rate of 0.0020ifmmodepmelse extpmfi{}0.0007 ${mathrm{kbar}}^{mathrm{ensuremath{-}}1}$. From this result, we conclude that the previous determinations of the band-offset values of GaAs/${mathrm{Al}}_{mathit{x}}$${mathrm{Ga}}_{1mathrm{ensuremath{-}}mathit{x}}$As by high-pressure measurements overestimated (underestimated) the fractional conduction- (valence-) band offset by 0.06ifmmodepmelse extpmfi{}0.02, and the corrected ${mathit{Q}}_{mathit{c}}$ value at atmospheric pressure should be 0.63ifmmodepmelse extpmfi{}0.04.