Internal electric field in wurtzite ZnO/Zn0.78Mg0.22O quantum wells -: art. no. 241305
Internal electric field in wurtzite ZnO/Zn0.78Mg0.22O quantum wells -: art. no. 241305
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DOI：
10.1103/physrevb.72.241305
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发表时间：
2005-12-01
影响因子：
3.7
通讯作者：
Deparis, C
中科院分区：
文献类型：
--
作者：
Morhain, C;Bretagnon, T;Deparis, C
利用连续波、时间积分和时间分辨光致发光实验研究了纤锌矿ZnO/Zn 0. 78 Mg 0. 22 O量子威尔斯阱中激子的光学复合。通过比较实验结果与激子能量和振子强度的变分计算，我们确定的幅度（0.9 MV/cm）的纵向电场是由自发和压电极化引起的。量子限制斯塔克效应抵消量子限制效应的阱宽度大于3 nm，导致发射能量可以低于ZnO激子间隙0.5 eV，辐射寿命可以大于毫秒。
Continuous-wave, time-integrated, and time-resolved photoluminescence experiments are used to study the excitonic optical recombinations in wurtzite ZnO/Zn0.78Mg0.22O quantum wells of varying widths. By comparing experimental results with a variational calculation of excitonic energies and oscillator strengths, we determine the magnitude (0.9 MV/cm) of the longitudinal electric field that is induced by both spontaneous and piezoelectric polarizations. The quantum-confined Stark effect counteracts quantum confinement effects for well widths larger than 3 nm, leading to emission energies that can lie 0.5 eV below the ZnO excitonic gap and to radiative lifetimes that can be larger than milliseconds.