Single-dot spectroscopy of boron and phosphorus codoped silicon quantum dots

Kanno, Takashi; Sugimoto, Hiroshi; Fučíková, Anna; Valenta, J.; Fujii, Minoru

doi:10.1063/1.4965986

Cited by 13 publications

(12 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The presence of these donor and acceptor states lowers the energy gap from 2.59 eV, for the undoped Si‐NC, to 1.82 eV, for the co‐doped one. In large Si‐NCs, by engineering impurity location, co‐doping can be exploited to tune the energy of the gap from the visible range to values below the energy gap of the Si‐bulk, in agreement wth the experimental observations . Moreover, very recently Hori et al have demonstrated using photoemission yield spectroscopy and photoluminescence spectroscopy that for B and P codoped Si‐NCs with relatively large sizes both the HOMO and LUMO levels are within the band gap of bulk Si crystal, confirming that these are acceptor and donor levels, and that, with decreasing the size from 9 to 1 nm, the HOMO level becomes about 0.46 eV deep and the LUMO level about 0.47 eV shallow, in fair agreement with the theoretical outcomes …”

Section: Co‐dopingsupporting

confidence: 64%

“…It has, however, been shown that this quenching can be avoided when the Si‐NCs are simultaneously doped and compensated with B and P impurities. The co‐doped Si‐NCs exhibit PL energies red‐shifted with respect to those of the corresponding undoped Si‐NCs, moreover these energies can range from the visible to below the bandgap energy of the bulk Si . Thus, we will report here the outcomes of a systematic study of the structural, electronic and optical properties of B and P simultaneously doped Si‐NCs using ab initio DFT calculations .…”

Section: Co‐dopingmentioning

confidence: 99%

See 1 more Smart Citation

First Principle Studies of B and P Doped Si Nanocrystals

Marri

Degoli

Ossicini

2017

Physica Status Solidi (a)

View full text Add to dashboard Cite

The properties of n- and p-doped silicon nanocrystals obtained through ab initio calculations are reviewed here. The aim is the understanding of the effects induced by substitutional doping on the structural, electronic and optical properties of free-standing and matrix-embedded Si nanocrystals. The preferential positioning of the dopants and their effects on the structural properties with respect to the undoped case, as a function of the nanocrystals diameter and termination, are identified through total-energy considerations. The localization of the acceptor and donor related levels in the band gap of the Si nanocrystals, together with the impurity activation energy, are discussed as a function of the nanocrystals size. The dopant induced differences in the optical properties with respect to the undoped case are presented. Finally, the case of B and P co-doped nanocrystals is discussed showing that if carriers are perfectly compensated, the Si nanocrystals undergo a minor structural distortion around the impurities inducing a significant decrease of the impurities formation energies with respect to the single doped case. Due to co-doping, additional peaks are introduced in the absorption spectra, giving rise to a size-dependent red shift of the absorption spectra

show abstract

Section: Co‐dopingsupporting

confidence: 64%

Section: Co‐dopingmentioning

confidence: 99%

First Principle Studies of B and P Doped Si Nanocrystals

Marri

Degoli

Ossicini

2017

Physica Status Solidi (a)

View full text Add to dashboard Cite

show abstract

“…The very large difference of the fwhms indicates that there are some additional mechanisms to broaden the PL band in codoped Si QDs. As can be seen in Figure 3g, the fwhm of size-selected codoped Si QDs samples is larger than that of single codoped Si QDs (225 ± 40 meV) 40 (filled magenta square), despite the very small size distribution. This is another evidence of the existence of additional broadening mechanisms.…”

mentioning

confidence: 90%

Donor–Acceptor Pair Recombination in Size-Purified Silicon Quantum Dots

et al. 2018

Self Cite

View full text Add to dashboard Cite

Shallow impurity doping is an efficient route to tailor optical and electronic features of semiconductor quantum dots (QDs). However, the effect of doping is often smeared by the size, shape, and composition inhomogeneities. In this paper, we study optical properties of almost monodispersed spherical silicon (Si) QDs that are heavily doped with boron (B) and phosphorus (P). The narrow size distribution achieved by a size-separation process enables us to extract doping-induced phenomena clearly. The degree of doping-induced shrinkage of the optical band gap is obtained in a wide size range. Comparison of the optical band gap with theoretical calculations allow us to estimate the number of active donor−acceptor pairs in a QD. Furthermore, we found that the size and detection energy dependence of the luminescence decay rate is significantly modified below a critical diameter, that is ∼5.5 nm. In the diameter range above 5.5 nm, the luminescence decay rate is distributed in a wide range depending on the detection energy even in size-purified Si QDs. The distribution may arise from that of donor−acceptor distances. On the other hand, in the diameter range below 5.5 nm the detection energy dependence of the decay rate almost disappears. In this size range, which is smaller than twice of the effective Bohr radius of B and P in bulk Si crystal, the donor−acceptor distance is not a crucial factor to determine the recombination rate.

show abstract

“…Doped Si-NCs with diameter down to 3 nm have been synthetized using different strategies [89,90,110,111,112,113]. Among all, Fujii and coworkers developed an efficient procedure [114,115,116,117,118,119,120] where Si, SiO 2 , P 2 O 5 or B 2 O 3 were simultaneously sputter-deposited and then annealed in N 2 gas atmosphere. During annealing the B-or P-doped Si-NCs were grown in borosilicate (BSG) or phosphosilicate (PSG), i. e. B-or P-doped silica, glass matrices.…”

Section: Free-standing Nanocrystalsmentioning

confidence: 99%

“…More recently the same group reported a new method to obtain B and P codoped colloidal Si-NCs, where NCs were dispersed in methanol without a surface functionalization process [115,116,117,119]. To isolate Si-NCs from BPSG matrices, the BPSG films were dissolved in HF solution in ultrasonic bath.…”

Section: Codopingmentioning

confidence: 99%

Doped and codoped silicon nanocrystals: The role of surfaces and interfaces

Marri

Degoli

Ossicini

2017

Progress in Surface Science

View full text Add to dashboard Cite

Si nanocrystals have been extensively studied because of their novel properties and their potential applications in electronic, optoelectronic, photovoltaic, thermoelectric and biological devices. These new properties are achieved through the combination of the quantum confinement of carriers and the strong influence of surface chemistry. As in the case of bulk Si the tuning of the electronic, optical and transport properties is related to the possibility of doping, in a controlled way, the nanocrystals. This is a big challenge since several studies have revealed that doping in Si nanocrystals differs from the one of the bulk. Theory and experiments have underlined that doping and codoping are influenced by a large number of parameters such as size, shape, passivation and chemical environment of the silicon nanocrystals. However, the connection between these parameters and dopant localization as well as the occurrence of self-purification effects are still not clear. In this review we summarize the latest progress in this fascinating research field considering free-standing and matrix-embedded Si nanocrystals both from the theoretical and experimental point of view, with special attention given to the results obtained by ab-initio calculations and to size-, surface- and interface-induced effects

show abstract

Single-dot spectroscopy of boron and phosphorus codoped silicon quantum dots

Cited by 13 publications

References 60 publications

First Principle Studies of B and P Doped Si Nanocrystals

First Principle Studies of B and P Doped Si Nanocrystals

Donor–Acceptor Pair Recombination in Size-Purified Silicon Quantum Dots

Doped and codoped silicon nanocrystals: The role of surfaces and interfaces

Contact Info

Product

Resources

About