A low-temperature X-ray diffraction study of the CU2ZNSNSE4 thin films on a mo foil substrate

The Zn-rich and Cu-poor Cu2ZnSnSe4 (CZTSe) thin films were produced on flexible Mo foil by the three-step process. The XRD analysis demonstrates that the film mainly consists of CZTSe tetragonal phase and can contained ZnSe secondary phase. In addition, there are reflections of Mo and MoSe2. It was found that the crystal structure of the CZTSe films deposited on a Mo foil substrate was stable at low temperatures. The lattice parameters a and c are linearly decreasing in rang 5.707–5.637 and 11.394–11.298 A, respectively, with a change in the temperature of the X-ray measurements from the 300 to 100 K. The thermal expansion coefficient is 9.87 ? 10–6 K–1

Investigation of thin films MgAl2O4, deposited on the Si substrates by vacuum thermal evaporation

The article presents data on the study of X-ray structural and microstructural characteristics of thin films of aluminum-magnesium spinel MgAl2O4 deposited on Si substrates by vacuum thermal evaporation. MgAl2O4 films have a polycrystalline rhombic structure. The values of the unit cell parameters of MgAl2O4 are calculated. Scanning electron and atomic force microscopy showed that MgAl2O4 films have a densely packed structure without cracks. Physical characteristics and good adhesion of MgAl2O4 thin films to silicon substrates indicate their possibility of using in devices of opto- and microelectronics

Topography of the surface of precursors Cu-Zn-Sn layered electrochemically deposited on Mo / glass and Mo-foil

Рассмотрена возможность построения тонкопленочных фотопреобразователей на основе нетоксичных и доступных компонентов Cu2ZnSnSe4 на подложках из стекла и гибкой металлической фольги, которые открывают возможности применения гибких тонкопленочных фотопреобразователей. Полученные структуры исследованы методамиатомно-силовой и сканирующей электронной микроскопии.We discuss the abibility to construct thin-film solar cells based on non-toxic and available Cu2ZnSnSe4 components on glass substrates and flexible metal foil, which opens the possibility of application of flexible solar cells. The structures were studied by atomic force and scanning electron microscopy combined with energy dispersive spectrometry of secondary electrons

ИССЛЕДОВАНИЕ ТОНКИХ ПЛЕНОК Cu2ZnSnSe4 МЕТОДОМ АТОМНО-СИЛОВОЙ МИКРОСКОПИИ

In comparison to the traditional use of glass substrates, the thin films onto metal substrates offer improved device cooling, economical large-scale roll-to-roll processing, and applicability in lightweight, as well as flexible products. However, unlike glass, metal foils tend to exhibit rough surfaces. This article studies the substrate-type (Mo/glass and Мо-foil) effect on the topographic characteristics of the Cu2ZnSnSe4 films by atomic force microscopy (AFM). Cu2ZnSnSe4 thin films were prepared by the electrodeposition of stack copper/tin/copper/zinc (Cu/Sn/Cu/Zn) precursors, followed by selenization. AFM wasused to study the topographic characteristics of thin films, including grain size, surface roughness, and maximum height of the profile. It is shown that the films obtained on Mo/glass and Mo-foil substrates have similar roughness and in the both cases the grain structure is formed. The Cu2ZnSnSe4 thin films show relatively high surface roughness and maximum roughness profile height compared to Cu-Zn-Sn precursors. The increase in the surface roughness of the films was caused by the growth of grains during annealing and selenization processes.Методом атомно-силовой микроскопии исследовано влияние типа подложки на структуру и шероховатость поверхности пленок Cu2ZnSnSe4, полученных методом селенизации металлических прекурсоров Cu-Zn-Sn на подложках из стекла с подслоем молибдена и молибденовой фольги (Мо/стекло, Мо-фольга). Обнаружено, что пленки Cu2ZnSnSe4 на подложках Мо/стекло и Мо-фольга имеют близкие значения шероховатости и зернистую структуру. Пленки Cu2ZnSnSe4 имеют более высокие значения шероховатости и максимальной высоты неровности профиля, чем металлические прекурсоры Cu-Zn-Sn. Увеличение шероховатости при формировании пленок Cu2ZnSnSe4 из прекурсоров происходит за счет роста зерен в процессе отжига и селенизации

Temperature dependence of Raman scattering in the Cu2ZnSnSe4 thin films on a Ta foil substrate

The temperature dependence (in range from 24 to 290 K) of Raman spectroscopy of the Cu2ZnSnSe4 (CZTSe) films with Zn-rich (series A) and Zn-poor (series B) composition obtained on a Ta foil is investigated. Analisys and approximation by the Lorentz function of the CZTSe Raman spectra suggests that the CZTSe most intense Raman peak consists of two modes (at 192/189 and 194/195 cm−1), which are slightly shifted from each other. In addition, the Raman peaks around 192 and 189 cm−1 lead to asymmetric broadening of dominant peaks at 194 and 195 cm−1 in Raman spectra of the CZTSe films series A and B, respectively. In the case of the Sn-rich CZTSe films, we attribute of Raman peak around 189 cm−1 to SnSe2 compound. However in the case of the Snpoor CZTSe films, the observable shift is too high to assign confidently the 192 cm−1 band to a SnSe2 compound, which was not detected by XRD analysis. We suppose that this mode is attributed to disordered kesterite structure. The temperature dependence Raman spectra for both series of the CZTSe films shows that a change temperature from 290 to 24 K leads to position shift and narrowing of the CZTSe Raman A-modes. The calculated temperature coefficients and anharmonic constants in Klemens model approximations for temperature dependence of shift position and FWHM of the CZTSe A-modes shown that four-phonon process has dominant contribution in damping process and as a consequence in Raman spectrum changes for two series of the CZTSe films

Influence of the substrate type on the surface morphology of Cu2ZnSnSe4 thin films

Investigations into the influence of the substrate type (a glass substrate with a molybdenum sublayer, tantalum and molybdenum foils) on the surface morphology of Cu2ZnSnSe4 thin films obtained by selenization of electrochemically deposited and preliminary annealed metallic precursors are presented. Metal foils are attractive for use as substrates of solar cells in both ground and space objects due to their light weight, flexibility, and the possibility of using the commercial roll-to-roll technology of film fabrication, leading to a reduction in the cost. At different stages of Cu2ZnSnSe4 film preparation, their surface morphology is studied by atomic-force microscopy and scanning electron microscopy in combination with energydispersive spectrometry. The metal substrate morphology is demonstrated to have an insignificant effect on the surface morphology of Cu2ZnSnSe4 films, indicating that flexible-foil substrates are promising for the production of thin-film solar cells. Исследования влияния типа подложки (стеклянная подложка с подслоем молибдена, фольги тантала и молибдена) на морфологию поверхности тонких пленок Cu2ZnSnSe4, полученных методом Представлена ​​селенизация электрохимически осажденных и предварительно отожженных металлических прекурсоров. Металлическая фольга привлекательна для использования в качестве подложки солнечных элементов как на наземных, так и на космических объектах благодаря своему свету. вес, гибкость и возможность использования коммерческой технологии производства пленки Roll-to-Roll, что приводит к снижению стоимости. На разных этапах приготовления пленок Cu2ZnSnSe4 морфология их поверхности исследуется методами атомно-силовой микроскопии и сканирующей электронной микроскопии в сочетании с энергодисперсионными спектрометрия. Показано, что морфология металлической подложки незначительно влияет на морфология поверхности пленок Cu2ZnSnSe4, указывающая на перспективность подложек из гибкой фольги для производство тонкопленочных солнечных элементов

Temperature dependence of raman spectra of Cu2ZnSnSe4 thin films

For CZTSe tetragonal structured film prepared by selenization of layer-by-layer and pre-annealed Cu-Zn-Sn metal precursor on flexible Ta substrate, temperature dependencies of the position and full width at a half maximum for the A-modes (171 and 195 cm-1 ) were obtained in the 24–290 K temperature range and were successfully approximated by the linear and Klemens model equations. From the obtained dependencies, the coefficients of the Klemens equations, as well as the temperature coefficients for Raman shifts and peak widths were calculated

Microstructure and Raman scattering of Cu2ZnSnSe4 thin films deposited onto flexible metal substrates

Abstract—Cu2ZnSnSe4 thin films are produced by selenizing electrochemically layer-by-layer deposited and preliminarily annealed Cu–Zn–Sn precursors. For flexible metal substrates, Mo and Ta foils are used. The morphology, elemental and phase compositions, and crystal structure of Cu2ZnSnSe4 films are studied by scanning electron microscopy, X-ray spectral microanalysis, X-ray phase analysis, and Raman spectroscopy

Influence of Substrate Material on the Microstructure of Cu2ZnSnS4 Thin Films

Abstract: Cu2ZnSnS4 (CZTS) thin films were synthesized from subsequently electrochemically deposited Cu/Sn/Zn metal precursors on Mo, Ti and Ta foil substrates by sulfurization at 450 °C for 1 h. Polycrystalline CZTS films with the kesterite structure were formed on each substrate. The lattice parameters of CZTS in films are a = 5.414 ± 0.003 Å, c = 10.85 ± 0.02 Å for Mo substrate, a = 5.415 ± 0.001 Å, c = 10.78 ± 0.01 Å for Ti substrate and a = 5.420 ± 0.003 Å, c = 10.84 ± 0.01 Å for Ta substrate. The CZTS have an average grain sizes of about 53, 80 and 68 nm for Mo, Ti and Ta substrate respectively. The films showed two types of crystallites corresponding to CZTS and CuS phases. The films exhibit Cu-enrichment and the presence of CuS and ZnS secondary phases. Binary sulfides MoS2 and TaS2 were found in the films deposited on Mo and Ta substrates respectively