Electronics of Anion Hot Injection-Synthesized Te-Functionalized Kesterite Nanomaterial

Abstract

Metal chalcogenides such as copper zinc tin sulfide (CZTS) have been intensively studied as potential photovoltaic cell materials, but their viability have been marred by crystal defects and low open circuit potential (Voc) deficit, which affected their energy conversion efficiency. Strategies to improve on the properties of this material such as alloying with other elements have been explored and have yielded promising results. Here, we report the synthesis of CZTS and the partial substitution of S with Te via anion hot injection synthesis method to form a solid solution of a novel kesterite nanomaterial, namely, copper zinc tin sulfide telluride (CZTSTe). Particle-size analyzed via small angle X-ray scattering spectroscopy (SAXS) confirmed that CZTS and CZTSTe materials are nanostructured. Crystal planes values of 112, 200, 220 and 312 corresponding to the kesterite phase with tetragonal modification were revealed by the X-ray diffraction (XRD) spectroscopic analysis of CZTS and CZTSTe. The Raman spectroscopy confirmed the shifts at 281 cm−1 and 347 cm−1 for CZTS, and 124 cm−1, 149 cm−1 and 318 cm−1 for CZTSTe. High degradation rate and the production of hot electrons are very detrimental to the lifespan of photovoltaic cell (PVC) devices, and thus it is important to have PVC absorber layer materials that are thermally stable. Thermogravimetric analysis (TGA) analysis indicated a 10% improvement in the thermal stability of CZTSTe compared to CZTS at 650 °C. With improved electrical conductivity, low charge transfer resistance (Rct) and absorption in the visible region with a low bandgap energy (Eg) of 1.54 eV, the novel CZTSTe nanomaterials displayed favorable properties for photovoltaics application.

Optical Properties and Lattice Dynamics of Pure and S‐Alloyed Cu–Zn–Sn–Te Semiconductors: First‐Principles Calculations and Raman Scattering

“…Raman spectra of S‐alloyed CZT(Te–S) nanoparticles, presented in Figure 8 , reveal the appearance of an additional strong line around 328–330 cm −1 , very similar to what was reported in Ref. [23]. The position of this new line is very close to the one in pure CZTS, where it corresponds to one of the A‐modes.…”

“…The calculated bandgap magnitude was found to be 0.45 eV, a value smaller in comparison with experimental findings of 0.8–0.9 eV. [ 11–13,23 ] Taking into account the well‐known shortcoming of DFT in the determination of the bandgap value for semiconductors [ 24 ] and to facilitate a comparison of the electronic and optical properties with experiment, we performed a “scissor shift” of all valence band states by 0.4 eV, so that the calculated bandgap at the Brillouin zone center (Figure 1) matches the experimental value.…”

From medical strategy to foodborne prophylactic strategy: Stabilizing dental collagen with aloin

“…As illustrated in Figure 2a , peak I intensities were higher in the XRD pattern of the A‐DDC group, suggesting that aloin may induce a shorter lateral spacing between collagen molecules (Green et al., 2017 ). This conjecture is further supported by the observed increase in 2 θ angles of the diffraction peak I and III in the A‐DDC group, indicating that the addition of aloin reduces the spacing between collagen molecules (Ding et al., 2019 ; Nwambaekwe et al., 2021 ). Peak II, which can be seen at roughly 2 θ ~20°, is due to the diffusive scattering caused by the presence of random‐coil structures embedded within the collagen fibers (Giraud‐Guille et al., 2000 ).…”

Tb- and Eu-doped yttrium oxyselenides as novel absorber layers for superstrate thin-film photovoltaics: improved spectral optical absorption and green–red phosphor activation

“…In the case of the modified electrode, the data obtained revealed that the electrodes underwent three reactions that are capacitive. 24,[83][84][85] The circuit consisted of R s and two R ct 's which have been defined. R s and R ct of 133 Ω and 894 Ω, respectively, were obtained for bare SPCE.…”