Size and dopant-concentration dependence of photoluminescence properties of ion-implanted phosphorus- and boron-codoped Si nanocrystals
Size and dopant-concentration dependence of photoluminescence properties of ion-implanted phosphorus- and boron-codoped Si nanocrystals
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DOI：
10.1103/physrevb.91.165424
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发表时间：
2015-04
影响因子：
3.7
通讯作者：
Toshihiro Nakamura;S. Adachi;M. Fujii;H. Sugimoto;K. Miura;S. Yamamoto
中科院分区：
文献类型：
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作者：
Toshihiro Nakamura;S. Adachi;M. Fujii;H. Sugimoto;K. Miura;S. Yamamoto
研究了用溅射和离子注入相结合的方法制备的重磷（P）和硼（B）共掺杂硅纳米晶（Si NC）的光致发光（PL）特性与纳米尺寸和掺杂浓度的关系。我们发现重掺杂Si NC具有三个奇异的发光带A、B和C。随着掺杂浓度的增加，带A的峰值能量发生红移。该能带是由于在降低的Si-NC带隙处由杂质带的形成以及带尾效应引起的带间跃迁。随着纳米微晶尺寸的减小，PL红移变大，表明量子限制诱导的载流子掺杂效应的发生。带B和C的峰值能量与浓度和尺寸无关，表明这些带是由于缺陷和/或杂质相关的局域态之间的跃迁。带A示出比纯（未掺杂）Si NC中的PL带更强的热猝灭，其幅度取决于掺杂剂浓度。带A中较强的热猝灭可能是由于杂质带中电子的热致迁移。
We investigate the nanocrystallite-size and dopant-concentration dependence of the photoluminescence (PL) properties of heavily phosphorus- (P) and boron- (B) codoped Si nanocrystals (Si NCs), prepared using a combination of sputtering and ion implantation techniques. We find that the heavily doped Si NC exhibits three exotic luminescence bands, A, B, and C. The peak energy of band A redshifts with increasing dopant concentration. This band is due to the band-to-band transition at the reduced Si-NC band gap caused by the formation of impurity bands together with band-tailing effects. The PL redshift becomes large when the nanocrystallite size decreases, suggesting the occurrence of the quantum-confinement-induced carrier doping effect. The peak energies of bands B and C are independent of both the concentration and size, indicating that these bands are due to transitions between defect- and/or impurity-related localized states. Band A shows stronger thermal quenching than the PL band in pure (undoped) Si NCs, the magnitude of which depends on the dopant concentration. The stronger thermal quenching in band A is probably due to the thermally induced migration of electrons in the impurity band.