Narrow Results

Sn precursor layer was evaporated on a glass substrate by an electron-beam evaporation method and followed by selenization using Se powder. SnSe film was successfully prepared by adjusting the selenization temperature and selenization time. The phase, microstructure and optical properties of the SnSe films were studied by X-ray diffraction, Raman spectroscopy, Scanning Electron Microscopy, and UV-Vis-NIR spectrophotometer. The results demonstrated that the pure phase polycrystalline SnSe films with a band gap of 0.93 eV could be prepared by selenizing at 450${}^{\circ }$C for 60 min. Under the irradiation of a 980 nm laser with a power of 2 mW/cm², photoelectric response characteristics of the SnSe films were tested, and the response time and recovery time of the prepared film were 62 ms and 80 ms, respectively, indicating that the SnSe film had a large application prospect in near-infrared light detection.

Single-phase CuInSe₂ films were grown by high vapor selenization of CuIn alloy precursors within a partially closed graphite box. The CuIn precursors were prepared using Cu_xIn_y alloy targets with different composition rates under low vacuum level by a homemade sputtering system. The Cu and In composition rates of the used targets are 11:9, 10:10, and 9:11, respectively. The metallic precursor films were selenized using a two-step temperature profile, i.e. at 250°C and 400–500°C, respectively. The influence of the temperature at the second selenization step on the quality of the CIS absorbing layers was investigated. The CIS films were characterized by X-ray diffractometry, scanning electron microscopy, energy dispersive X-ray analysis, and Raman spectroscopy. The deposited CIS absorbers selenized at a high temperature of 500°C for 30 min exhibited a single-phase chalcopyrite structure with a preferential orientation in the (112) direction. These layers display uniform, large, and densely packed crystals with a grain size of about 3–5 μm. Cadmium sulfide buffer layer was manufactured by chemical bath deposition method. Bilayers ZnO/ZnO:Al were prepared by RF magnetron sputtering deposition. CIS solar cells with an efficiency of about 6.5% were produced without antireflective films. The method to fabricate CIS solar cells by a combination of the low vacuum sputtering deposition and the graphite box selenization process has provided a simple control process and shown a promising potential for developing high efficient and low-cost CuInSe₂ solar cells.

A simple and hydrazine-free solution-based approach for depositing Cu₂ZnSnS₄ (CZTS) and Cu₂ZnSn(S,Se)₄ (CZTSSe) absorber layers is reported. The process involves incorporating metal salts (Cu(CH₃COO)₂, Zn(CH₃COO)₂, SnCl₂) and thiourea into a single pyridine-based solution, spin-coating a precursor film, and sulfurizing with sulfur powders or selenizing using Se pellets in an inert atmosphere, to form the desired CZTS or CZTSSe films. X-ray diffraction and Raman spectra studies show that kesterite CZTS and CZTSSe are formed after sulfurization and selenization, respectively. The selenized CZTSSe displays higher crystallinity than the sulfurized CZTS. Photovoltaic devices (glass/Mo/CZTSSe/CdS/i-ZnO/n-ZnO/A) employing the solution precursor selenized at 500°C have yielded power conversion efficiency of 1.44% under AM 1.5 illumination.

We reported the growth of CZTSSe thin films on Mo-coated SLG substrates by the two-step approach which includes the deposition of precursor films by the magnetron sputtering method at room temperature followed by selenization of the precursor films at 560^∘C. Formation of CZTSSe films with the kesterite structure was confirmed by XRD and Raman spectroscopy analyses. The films are slightly Cu-rich and Zn-deficient. SEM study shown that the films have uniform surface morphology and densely packed structure without any voids and cracks.

We report on surface nanostructuring of Cu(In,Ga)Se₂ (CIGS) films using inductively coupled argon plasma treatment with the ion energy of 25–30eV within 30–120s. The films were fabricated on glass substrates using the selenization method and had a polycrystalline structure. We demonstrate that the plasma treatment results in the formation of tip-shaped nanostructure arrays with the geometrical parameters controlled by the treatment duration. The features of the surface nanostructuring using low energy ions are discussed.

PbSe nanostructures were synthesized by selenization of lead sheets in a chemical vapor deposition (CVD) set-up under a selenium ambiance. The lead sheets were placed in the different temperature zones, between 300°C and 450°C. Field emission scanning electron microscope (FESEM) images showed that, PbSe nanostructures grown on the lead sheets with different morphologies. PbSe nanostructures with flakes shape were grown on the lead sheets that were placed in the lower temperature, while PbSe nanocubes and nanorods, which were grown on the nanocubes, were grown on the lead sheets in the higher temperature. The phase and composition of the product were identified by X-ray diffraction (XRD) pattern and X-ray photoelectron spectra (XPS). The XRD and XPS results showed that, the PbSe phase was started to form after 350°C and completed at 450°C. However, the XPS results showed that the Se concentration was different in the samples. In addition, Raman measurements confirmed the XRD and XPS results and indicated three Raman active modes, which belonged to PbSe phase for the nanostructures. The optical properties of the products were characterized by UV–Vis. The optical characterization results showed a band gap for the PbSe nanostructures in the infrared region.

Pure nickel nanoparticles with diameter around 100 nm were prepared with a moderate hydrothermal method. The matrix was then selenized into Ni${}_{0.85}$Se particles in a Se vapor without any damage to their original morphologies. The as-prepared N${}_{\mathrm{\text{i}}0.85}$Se and Ni nanoparticles were then used as counter electrodes (CEs) in dye-sensitized solar cells. It was found that the performance of the cell with Ni${}_{0.85}$Se as counter electrode is enhanced by nearly two times in contrast to the one with Ni as CEs. This provides a new method to fabricate optional counter electrode for Pt.

The anisotype HJ 𝜌-cu₂ZnSnSe₄/ n-GaAs was obtained, for the first time, by selenization of base metal layers that were previously thermally deposited on a GaAs substrate. The heterostructures created discuss both current-voltage properties and current transmission mechanisms. The forward bias was found to be characterized by currents limited by space charge, tunneling and recombination processes. In the case of reverse bias, currents predominate, which are limited by the space charge in mobility mode.