An unusual emission-I line has been observed in the photoluminescence spectra of MBE GaAs/AlAs MQW at 4.2K.Its half width is 6.5-9meV with peak energy Located between the near band transition and the free electrons to...An unusual emission-I line has been observed in the photoluminescence spectra of MBE GaAs/AlAs MQW at 4.2K.Its half width is 6.5-9meV with peak energy Located between the near band transition and the free electrons to carbon acceptors transition in bulk GaAs.The peak energy increases roughly linearly with the logarithm of the excitation power.The emission intensity decreases with the increase of temperature and disappears at about 15K.展开更多
We report a far-infrared absorption study of internal transitions of shallow Be acceptors in both bulk GaAs and a series of δ-doped GaAs/AlAs multiple quantum well samples with well thicknesses of 20,15 and 10 nm. Lo...We report a far-infrared absorption study of internal transitions of shallow Be acceptors in both bulk GaAs and a series of δ-doped GaAs/AlAs multiple quantum well samples with well thicknesses of 20,15 and 10 nm. Low temperature far-infrared absorp-tion measurements clearly show three principal absorption lines due to transitions of Be-acceptor states from the ground state to the first three odd-parity excited states,respec-tively. Using a variational principle,the 2p-1s transition energies of quantum confined Be acceptors are calculated as a function of the well width. It is found that the theoretical calculation of the 2pz → 1s transitions is in good agreement with the D-like line experi-mental data.展开更多
用分子束外延 (MBE)设备制备了 Ga As/ Al As和 Ga As/ Si/ Al As异质结 ,通过 XPS分别研究了异质结界面处 Si层厚度为 0 .5 ML 和 1ML 对异质结带阶的调节 ,得到最大调节量为 0 .2 e V;通过 C- V法研究了异质结的Ga As层在不同温度下...用分子束外延 (MBE)设备制备了 Ga As/ Al As和 Ga As/ Si/ Al As异质结 ,通过 XPS分别研究了异质结界面处 Si层厚度为 0 .5 ML 和 1ML 对异质结带阶的调节 ,得到最大调节量为 0 .2 e V;通过 C- V法研究了异质结的Ga As层在不同温度下生长对 0 .5 ML Si夹层的影响 ,得到 Si夹层的空间分布随 Ga As层生长温度的升高而扩散增强的温度效应 ,通过深能级瞬态谱 (DL TS)研究了在上述不同温度下生长的 Ga As层的晶体质量 .展开更多
文摘An unusual emission-I line has been observed in the photoluminescence spectra of MBE GaAs/AlAs MQW at 4.2K.Its half width is 6.5-9meV with peak energy Located between the near band transition and the free electrons to carbon acceptors transition in bulk GaAs.The peak energy increases roughly linearly with the logarithm of the excitation power.The emission intensity decreases with the increase of temperature and disappears at about 15K.
文摘We report a far-infrared absorption study of internal transitions of shallow Be acceptors in both bulk GaAs and a series of δ-doped GaAs/AlAs multiple quantum well samples with well thicknesses of 20,15 and 10 nm. Low temperature far-infrared absorp-tion measurements clearly show three principal absorption lines due to transitions of Be-acceptor states from the ground state to the first three odd-parity excited states,respec-tively. Using a variational principle,the 2p-1s transition energies of quantum confined Be acceptors are calculated as a function of the well width. It is found that the theoretical calculation of the 2pz → 1s transitions is in good agreement with the D-like line experi-mental data.
文摘用分子束外延 (MBE)设备制备了 Ga As/ Al As和 Ga As/ Si/ Al As异质结 ,通过 XPS分别研究了异质结界面处 Si层厚度为 0 .5 ML 和 1ML 对异质结带阶的调节 ,得到最大调节量为 0 .2 e V;通过 C- V法研究了异质结的Ga As层在不同温度下生长对 0 .5 ML Si夹层的影响 ,得到 Si夹层的空间分布随 Ga As层生长温度的升高而扩散增强的温度效应 ,通过深能级瞬态谱 (DL TS)研究了在上述不同温度下生长的 Ga As层的晶体质量 .
