Supplementary Material, SLR_729423_Appendix_2 – The basic continuity hypothesis of L1 to L2 production

<p>Supplementary Material, SLR_729423_Appendix_2 for The basic continuity hypothesis of L1 to L2 production by Francesco Romano in Second Language Research</p

Photoinduced Electron-Transfer Quenching of Luminescent Silicon Nanocrystals as a Way To Estimate the Position of the Conduction and Valence Bands by Marcus Theory

Photoluminescence of silicon nanocrystals (SiNCs) in the presence of a series of quinone electron acceptors and ferrocene electron donors is quenched by oxidative and reductive electron transfer dynamic processes, respectively. The rate of these processes is investigated as a function of (a) the thermodynamic driving force of the reaction, by changing the reduction potentials of the acceptor or donor molecules, (b) the dimension of SiNCs (diameter = 3.2 or 5.0 nm), (c) the surface capping layer on SiNCs (dodecyl or ethylbenzene groups), and (d) the solvent polarity (toluene vs dichloromethane). The results were interpreted within the classical Marcus theory, enabling us to estimate the position of the valence and conduction bands, as well as the reorganization energy (particularly small, as expected for quantum dots) and electronic transmission coefficients. The last parameter is in the range 10^–5–10^–6, demonstrating the nonadiabaticity of the process, and it decreases upon increasing the SiNC dimensions: this result is in line with a larger number of excitons generated in the inner silicon core for larger SiNCs and thus resulting in a lower electronic coupling with the quencher molecules

Remote controlled irradiation system.

<p>Photograph of the remote controlled irradiation system. During ion beam exposure each hole contained a sample holder with 12 seeds according to the arrangement shown in the inset.</p

Time trend of Delayed Luminescence emission from seeds.

<p>Typical Time trend of the DL emission from a seed at different irradiation doses: (○) native, (■) 100 Gy, (△) 1000 Gy. Data refers to the 450 nm spectral component. Markers denotes average values of 12 seeds. Standard errors are smaller than markers size.</p

Relation between seedling growth and delayed luminescence yield.

<p>Normalized growth NG as a function of the normalized emission NE_as, after subtraction of DL emission of non-germinating seeds, for the two spectral components at (○) 450 nm, (△) 650 Gy. (^____) Best fit of both set of data according to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167998#pone.0167998.e004" target="_blank">Eq (4)</a>. Markers denote average values on the whole seeds data set at the same dose. Bars denote standard errors.</p

Relation between delayed luminescence yield and irradiation dose.

<p>DL total number of counts, normalized to the native ones (<i>NE</i>) as a function of the absorbed dose (<i>D</i>) for the two spectral components: (○) 450 nm, (△) 650 Gy, (^____) best fit of the experimental data according to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167998#pone.0167998.e003" target="_blank">Eq (3)</a>. Markers denote average values on the whole seeds data set at every dose (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167998#pone.0167998.t001" target="_blank">Table 1</a>). Vertical bars denote standard errors.</p

Number of seeds for germination and DL test at every ion beam dose.

<p>Number of seeds for germination and DL test at every ion beam dose.</p

Relation between seedling length and irradiation dose.

<p>(○) average values of the normalized seedlings length <i>NG</i> as a function of the irradiation dose. (^____) best fit of the experimental data according to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167998#pone.0167998.e001" target="_blank">Eq (1)</a>. In the little frame the same data at low doses fitted according to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167998#pone.0167998.e002" target="_blank">Eq (2)</a>. Inset: Photograph of a regularly grown (a) and a poorly grown (b) seedling at the same growing day.</p

Alveolar plate for seeds' growth.

<p>Photograph of the polycarbonate alveolar plate where the seeds were grown under controlled conditions. In the inset, the scheme of the plates’ arrangement inside the thermostatic chamber is shown.</p