Size-controlled Si quantum dots embedded in B-doped SiNx/Si3N4 superlatice for Si quantum dot solar cells

Near-IR Emitting Si Nanocrystals Fabricated by Thermal Annealing of SiNx/Si3N4 Multilayers

“…In this spectral region, no contribution from radiative defects is expected. Similar near-IR luminescence with the peaks in the range 1.4-1.7 eV was shown recently from annealed B-doped SiN x /Si 3 N 4 multilayer films with Si quantum dots produced by magnetron sputtering; however, no time-resolved PL data were provided [10].…”

“…2019, 9, 4725 2 of 9 (SL) approach [7][8][9]. This approach allows one to limit the maximum size of Si NCs by deposition of Si-rich layers, wherein Si NCs are self-organized during high temperature annealing, alternating with stoichiometric barrier layers, which should remain unchanged [9,10]. However, as shown recently, the stability of multilayers against annealing depends on the thickness of layers and treatment temperature, thus partial or total intermixing of layered structure may occur, and Si NCs with the size exceeding the thickness of initial of Si-rich layers may be formed [11,12].…”

“…A characteristic lifetime of such defect-related PL is of order of nanoseconds [18], while Si NC-related PL is known to possess much longer decay times in a microsecond range [3,12]. Hence, time-resolved PL measurements are important for the correct identification of PL source, which are often not presented in papers dedicated to Si NC luminescence in Si 3 N 4 [9,10,13].…”

Structure‐related current transport and photoluminescence in SiOxNy and SiNx based superlattices with Si nanocrystals

“…All spectra are characterized by peaks with similar full width at half maximum (FWHM ≈ 0.3 eV) and almost Gaussian profile, the maxima of the bands belong in the range from about 1.3–1.6 eV. Such position of PL peaks is typical for Si‐NCs related quantum confined luminescence . Hence we assume that Si‐NCs were self‐organized in all high temperature annealed SLs under study, even though the c‐Si related XRD signal was not detected for all the samples.…”

“…Indeed, both stoichiometric and Si‐rich silicon nitride are known to possess luminescent centers , and their emission might be easily misinterpreted as Si‐NCs related . Analyzing the known to date PL data on Si‐rich nitrides, one can notice that the defect‐related PL is more often characterized by a relatively broad peak (> 0.5 eV) with the maximum located above ∼1.8–2 eV , while the quantum confined PL − by a significantly more narrow peak located usually below ∼1.9 eV . According to these observations and taking into account the size‐dependent peak shift one may ascribe the PL of our 1150 °C annealed SON and SN samples to QC effect in Si‐NCs embedded in either silicon oxynitride or pure nitride matrices.…”