Size-Dependence of Acceptor and Donor Levels of Boron and Phosphorus Codoped Colloidal Silicon Nanocrystals
Size-Dependence of Acceptor and Donor Levels of Boron and Phosphorus Codoped Colloidal Silicon Nanocrystals
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DOI：
10.1021/acs.nanolett.6b00225
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发表时间：
2016-04-01
期刊：
影响因子：
10.8
通讯作者：
Fujii, Minoru
中科院分区：
文献类型：
--
作者：
Hori, Yusuke;Kano, Shinya;Fujii, Minoru
用光电子产额谱和光致发光光谱研究了B和P共掺杂的硅纳米晶(NCS)的B(B)受主和P(P)施主能级的尺寸依赖关系。在相对较大的Si-NCS中，这两个能级都在体硅带隙内。与价带和导带边缘相比，能级的尺寸依赖性要小得多。研究了B、P共掺Si-NCS的费米能级。研究发现，较大的共掺杂Si-NCS的费米能级接近价带，并且随着尺寸的减小而接近禁带的中间位置。结果表明，在一定尺寸以下，无论样品中B和P的平均浓度如何，都优先生长出完全补偿的Si-NCs，即具有完全相同数量的活性B和P的Si-NCs。
Size dependence of the boron (B) acceptor and phosphorus (P) donor levels of silicon (Si) nanocrystals (NCs) measured from the vacuum level was obtained in a very wide size range from 1 to 9 nm in diameter by photoemission yield spectroscopy and photoluminescence spectroscopy for B and P codoped Si-NCs. In relatively large Si-NCs, both levels are within the bulk Si band gap. The levels exhibited much smaller size dependence compared to the valence band and conduction band edges. The Fermi level of B and P codoped Si-NCs was also studied. It was found that the Fermi level of relatively large codoped Si-NCs is close to the valence band and it approaches the middle of the band gap with decreasing the size. The results suggest that below a certain size perfectly compensated Si-NCs, that is, Si-NCs with exactly the same number of active B and P, are preferentially grown, irrespective of average B and P concentrations in samples.