Donor bound-exciton excited states in zinc selenide
Donor bound-exciton excited states in zinc selenide
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硒化锌中的供体束缚激子激发态
DOI：
10.1103/physrevb.23.4888
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发表时间：
1981
影响因子：
3.7
通讯作者：
R. Bhargava
中科院分区：
文献类型：
--
作者：
P. J. Dean;D. Herbert;C. Werkhoven;B. Fitzpatrick;R. Bhargava
用可调谐染料激光器对相对纯的气相生长和溶液生长的ZnSe单晶进行了选择性光致发光(SPL)和光致发光激发(PLE)光谱的精确测量。通过参考Merz等人的工作确定了供体物种。对于1s，2s，p的激发能有非常精确的一致性，但对于绝对光子能量却不是这样。一个新的束缚激子(BE)正好落在供体BE的上方，表明不涉及另一个供体物种。得到了有效质量施主结合能、电子有效质量、静态介电常数、自由激子(FE)内结合能和自由粒子带隙的改进值。与中性施主、中性受主和其他Be原子相比，电离激子的PLE谱有很大的不同，这是由于前者的激发通道中自由电子-空穴对占优势，后者的激发通道中自由电子空穴对占优势。在电离施主发光的PLE中出现朗道能级效应。新的激发态出现在$n=2$Fe能级以下，SPL表明与中性施主有关。它们的波函数特性与恰好低于$n=1$FE的施主束缚激子激发态形成了对比。讨论了在电离施主Be中观察到的分裂的性质。
Accurate measurements of donors in selective photoluminescence (SPL) and photoluminescence excitation (PLE) spectra have been made with a tunable dye laser for relatively pure vapor and solution-grown single crystals of ZnSe. The donor species are identified by reference to the work of Merz et al. Very accurate agreement is found for the $1s\ensuremath{-}2s,p$ excitation energies, though not for the absolute photon energies. A new bound exciton (BE) falling just above the donor BE is shown not to involve a further donor species. Improved values are derived for effective-mass donor binding energy, the electron effective mass, static dielectric constant, internal binding energy of the free exciton (FE), and the free-particle band gap in ZnSe. Large differences in the PLE spectra of excitons bound to ionized compared with neutral donors, as well as for neutral acceptors and other BE, are attributed to the dominance of free electron-hole pairs in the excitation channel for the former and FE for the latter luminescence. Landau-level effects appear in the PLE for ionized donor luminescence. New excited BE states appearing just below the $n=2$ FE energies are shown by SPL to involve neutral donors. Their wave-function character is contrasted with the donor bound-exciton excited states just below the $n=1$ FE. The nature of splittings observed in ionized donor BE is discussed.