Chalcogen Elements Research Articles

Band 3/anion exchanger 1/solute carrier family 4 member 1 expression as determinant of cellular sensitivity to selenite exposure

Selenium is a chalcogen element that is essential in animals, but is highly toxic when ingested above the nutritional requirement. Selenite is used as a supplement in patients receiving total parenteral nutrition. However, the therapeutic and toxic doses of selenite are separated by a narrow range. This ambivalent character of selenite implies the presence of cellular mechanisms that precisely control selenite homeostasis. Here, we investigated mechanisms that determine cellular susceptibility to selenite exposure. The resistance to selenite exposure was significantly different among cell lines. We determined the expression levels of TPMT (thiopurine S-methyltransferase) and SLC4A1 (solute carrier family 4 member 1), which encode selenium methyltransferase and selenite transporter, respectively. We also examined the effect of inhibition of Band 3 protein activity, which is encoded by SLC4A1, on the cellular sensitivity to selenite. The data suggest that the expression level of SLC4A1 is the determinant of cellular sensitivity to selenite.

Spin-Orbit Coupling and Spin-Polarized Electronic Structures of Janus Vanadium-Dichalcogenide Monolayers: First-Principles Calculations.

Phonon and spintronic structures of monolayered Janus vanadium-dichalcogenide compounds are calculated by the first-principles schemes of pseudopotential plane-wave based on spin-density functional theory, to study dynamic structural stability and electronic spin-splitting due to spin-orbit coupling (SOC) and spin polarization. Geometry optimizations and phonon-dispersion spectra demonstrate that vanadium-dichalcogenide monolayers possess a high enough cohesive energy, while VSTe and VTe2 monolayers specially possess a relatively higher in-plane elastic coefficient and represent a dynamically stable structure without any virtual frequency of atomic vibration modes. Atomic population charges and electron density differences demonstrate that V–Te covalent bonds cause a high electrostatic potential gradient perpendicular to layer-plane internal VSTe and VSeTe monolayers. The spin polarization of vanadium 3d-orbital component causes a pronounced energetic spin-splitting of electronic-states near the Fermi level, leading to a semimetal band-structure and increasing optoelectronic band-gap. Rashba spin-splitting around G point in Brillouin zone can be specifically introduced into Janus VSeTe monolayer by strong chalcogen SOC together with a high intrinsic electric field (potential gradient) perpendicular to layer-plane. The vertical splitting of band-edge at K point can be enhanced by a stronger SOC of the chalcogen elements with larger atom numbers for constituting Janus V-dichalcogenide monolayers. The collinear spin-polarization causes the band-edge spin-splitting across Fermi level and leads to a ferrimagnetic order in layer-plane between V and chalcogen cations with higher α and β spin densities, respectively, which accounts for a large net spin as manifested more apparently in VSeTe monolayer. In a conclusion for Janus vanadium-dichalcogenide monolayers, the significant Rashba splitting with an enhanced K-point vertical splitting can be effectively introduced by a strong SOC in VSeTe monolayer, which simultaneously represents the largest net spin of 1.64 (ћ/2) per unit cell. The present study provides a normative scheme for first-principles electronic structure calculations of spintronic low-dimensional materials, and suggests a prospective extension of two-dimensional compound materials applied to spintronics.

First-principles insight into the interfacial properties of epitaxial Bi2O2X (X = S, Se, Te) on SrTiO3 substrates

In this work, we construct the Bi2O2X/SrTiO3 heterostructures and explore the geometric, electronic, optical, and transport characteristics based on density functional theory (DFT) in integration with non-equilibrium Green's function (NEGF) calculations. The influence of chalcogen elements on the Bi2O2X/SrTiO3 interface is discussed. Eighteen different interface configurations with different terminations are designed and the most stable configurations are determined. The interfaces between SrO-terminated SrTiO3 and O-terminated Bi2O2X show the highest cohesive energy and strongest charge interaction regardless of the chalcogen elements, which is the best interfacial stability. Among these interfaces, the Bi2O2S/SrTiO3 interface were found to possess the largest cohesive energy and best stability due to the fewer and lower surface states around the Fermi level. By contrast, the Bi2O2Te/SrTiO3 interface shows the largest dielectric function among these three interfacial systems leading to better optical property. In addition, the electronic transport properties reveal that Bi2O2Te/SrTiO3 has the largest transmission coefficient indicates enhanced electron transport and electric current at the interface.

Selective crystal growth of indium selenide compounds from saturated solutions grown in a selenium vapor

Indium selenide compounds are promising materials for energy conversion, spintronic applications, and chemical sensing. However, it is difficult to grow stoichiometric indium selenide crystals due to the high equilibrium selenium vapor pressure and the complicated phase equilibrium system of indium selenide compounds. In this paper, we apply a novel and convenient crystal growth method, in which the saturated solution is grown by the application of a selenium vapor. In this method, selenium vapor at a pressure higher than the saturated vapor pressure is applied to molten indium, such that the selenium continuously dissolves into the indium solution until the solubility at the growth temperature is reached; then a slow cooling process results in crystallization. The selenium dose is matched to its solubility so that indium selenide compounds can be selectively grown just by controlling the temperature without the need to consider the chemical ratio in the solution. The pressure of the vapor is controlled during the whole growth process so that any deviation from a stoichiometric composition in the crystal can be controlled. Both InSe and In2Se3 were successfully grown using this method, and we have investigated the growth mechanism and found the growth window for each compound. This study presents a novel and convenient approach to fabricating transitional metal chalcogenides without deficiencies in the chalcogen element.

Achieving Efficient NIR-II Type-I Photosensitizers for Photodynamic/Photothermal Therapy upon Regulating Chalcogen Elements.

Second near-infrared (NIR-II) window type-I photosensitizers have intrinsic advantages in photodynamic/photothermal therapy (PDT/PTT) of some malignant tumors with deep infiltration, large size, complicated location, and low possibility of surgery/radiotherapy. Herein, three chalcogen-element-based donor-acceptor-type semiconducting polymers (poly[2,2″-((E)-4,4″-bis(2-octyldodecyl)-[6,6″-bithieno[3,2-b]pyrrolylidene]-5,5″(4H,4″H)-dione)-alt-2,5-(thiophene)] (PTS), poly[2,2″-((E)-4,4″-bis(2-octyldodecyl)-[6,6″-bithieno[3,2-b]pyrrolylidene]-5,5″(4H,4″H)-dione)-alt-2,5-(selenophene)] (PTSe), and poly[2,2″-((E)-4,4″-bis(2-octyldodecyl)-[6,6″-bithieno[3,2-b]pyrrolylidene]-5,5″(4H,4'H)-dione)-alt-2,5-(tellurophene)] (PTTe)) are synthesized and fully characterized, demonstrating strong absorption in the NIR-II region. Upon adjusting the chalcogen elements, the intramolecular charge-transfer characteristics and the heavy-atom effect are tuned to enhance the intersystem crossing rate, improving the photodynamic effect. Moreover, the energy levels and Gibbs free energies are tuned to facilitate the type-I photodynamic process. As a result, PTTe nanoparticles (NPs) produce superoxide anion radicals (O2 •- ) more efficiently and demonstrate higher photothermal conversion efficiency than PTS and PTSe NPs upon NIR-II (1064nm) laser irradiation, exhibiting unprecedented NIR-II type-I PDT/PTT performance in vitro and in vivo. This work provides ideas for achieving high-performance NIR-II type-I PDT/PTT semiconducting polymers for hypoxic oncotherapy.

Transition Metal Dichalcogenides (TMDC)-Based Nanozymes for Biosensing and Therapeutic Applications.

Nanozymes, a type of nanomaterial with enzyme-like properties, are a promising alternative to natural enzymes. In particular, transition metal dichalcogenides (TMDCs, with the general formula MX2, where M represents a transition metal and X is a chalcogen element)-based nanozymes have demonstrated exceptional potential in the healthcare and diagnostic sectors. TMDCs have different enzymatic properties due to their unique nano-architecture, high surface area, and semiconducting properties with tunable band gaps. Furthermore, the compatibility of TMDCs with various chemical or physical modification strategies provide a simple and scalable way to engineer and control their enzymatic activity. Here, we discuss recent advances made with TMDC-based nanozymes for biosensing and therapeutic applications. We also discuss their synthesis strategies, various enzymatic properties, current challenges, and the outlook for future developments in this field.

Amorphous Hf–O–Te as a selector via a modified conduction mechanism by Te content control

The resistive switching of an Ovonic threshold switch (OTS) material is characterized by Poole-Frenkel (PF) conduction and atomic rearrangement originating from chalcogen defects; thus, most OTS materials contain Se and/or Te. In addition to these chalcogen elements, As is included to form rigid amorphous networks. However, since As and Se are toxic, the development of As- and Se-free OTS materials is strongly desired. To realize As-free OTS materials that exhibit a comparable or even superior performance, a new strategy for material development should be established. In this study, we aimed to add Te to a HfO2 insulator to convert the electric conduction mechanism to PF conduction for realizing a selector function. The optical and electrical characteristics of Hf–O–Te ternary amorphous films with various Te contents were investigated. By changing the Te content, the optical bandgap was found to be tuned in the range of 0.46–5 eV, concomitantly with the modification of electrical properties. The electrical characteristics of the films demonstrated a strong compositional dependence, and Hf0.24O0.55Te0.21 was found to exhibit PF conduction, resulting in a selector function with a selectivity of approximately two orders of magnitude. These results indicate that the inclusion of a heavy chalcogen, such as Te, is effective in altering the conduction mechanism of transition-metal oxides and realizing a selector function.

High electron affinity triggered by lithium coordination: quasi-chalcogen properties of Li2Sn8Be.

This work puts forward an unusual but rational strategy to design superatoms mimicking the properties of group via elements. A new dianion with closo-configuration, namely Li2Sn8Be2-, has been obtained by decorating endohedral Zintl ion Sn8Be4- with two Li ligands. Its neutral counterpart, namely Li2Sn8Be, exhibits a high electron affinity of 2.526 eV, which not only exceeds that of the Sn8Be cluster but is higher than those of chalcogen elements. Li2Sn8Be has the potential to form stable ionic compounds with lithium, calcium, and even superalkali and superalkali-earth-metal atoms, and has an oxidation state of -2 therein. Besides, compound analogues of CO, O22-, H2O2, and Li2O2 can also be obtained with Li2Sn8Be serving as the building block. The striking resemblance between Li2Sn8Be and oxygen-group elements not only qualifies it for membership of the superatom family, but further collaborates the theoretical framework of the "three-dimensional periodic table".

Electrical and Optical Doping of Silicon by Pulsed-Laser Melting

Over four decades ago, pulsed-laser melting, or pulsed-laser annealing as it was termed at that time, was the subject of intense study as a potential advance in silicon device processing. In particular, it was found that nanosecond laser melting of the near-surface of silicon and subsequent liquid phase epitaxy could not only very effectively remove lattice disorder following ion implantation, but could achieve dopant electrical activities exceeding equilibrium solubility limits. However, when it was realised that solid phase annealing at longer time scales could achieve similar results, interest in pulsed-laser melting waned for over two decades as a processing method for silicon devices. With the emergence of flat panel displays in the 1990s, pulsed-laser melting was found to offer an attractive solution for large area crystallisation of amorphous silicon and dopant activation. This method gave improved thin film transistors used in the panel backplane to define the pixelation of displays. For this application, ultra-rapid pulsed laser melting remains the crystallisation method of choice since the heating is confined to the silicon thin film and the underlying glass or plastic substrates are protected from thermal degradation. This article will be organised chronologically, but treatment naturally divides into the two main topics: (1) an electrical doping research focus up until around 2000, and (2) optical doping as the research focus after that time. In the first part of this article, the early pulsed-laser annealing studies for electrical doping of silicon are reviewed, followed by the more recent use of pulsed-lasers for flat panel display fabrication. In terms of the second topic of this review, optical doping of silicon for efficient infrared light detection, this process requires deep level impurities to be introduced into the silicon lattice at high concentrations to form an intermediate band within the silicon bandgap. The chalcogen elements and then transition metals were investigated from the early 2000s since they can provide the required deep levels in silicon. However, their low solid solubilities necessitated ultra-rapid pulsed-laser melting to achieve supersaturation in silicon many orders of magnitude beyond the equilibrium solid solubility. Although infrared light absorption has been demonstrated using this approach, significant challenges were encountered in attempting to achieve efficient optical doping in such cases, or hyperdoping as it has been termed. Issues that limit this approach include: lateral and surface impurity segregation during solidification from the melt, leading to defective filaments throughout the doped layer; and poor efficiency of collection of photo-induced carriers necessary for the fabrication of photodetectors. The history and current status of optical hyperdoping of silicon with deep level impurities is reviewed in the second part of this article.

Effect of Point Defects on Electronic Structure of Monolayer GeS.

Using density functional theory calculations, atomic and electronic structure of defects in monolayer GeS were investigated by focusing on the effects of vacancies and substitutional atoms. We chose group IV or chalcogen elements as substitutional ones, which substitute for Ge or S in GeS. It was found that the bandgap of GeS with substitutional atoms is close to that of pristine GeS, while the bandgap of GeS with Ge or S vacancies was smaller than that of pristine GeS. In terms of formation energy, monolayer GeS with Ge vacancies is more stable than that with S vacancies, and notably GeS with Ge substituted with Sn is most favorable within the range of chemical potential considered. Defects affect the piezoelectric properties depending on vacancies or substitutional atoms. Especially, GeS with substitutional atoms has almost the same piezoelectric stress coefficients as pristine GeS while having lower piezoelectric strain coefficients but still much higher than other 2D materials. It is therefore concluded that Sn can effectively heal Ge vacancy in GeS, keeping high piezoelectric strain coefficients.

Structural, electronic, and transport properties of Janus GaInX 2 (X = S, Se, Te) monolayers: first-principles study

Two-dimensional Janus monolayers have outstanding electronic and transport properties due to their asymmetric atomic structures. In the present work, we systematically study the structural, electronic, and transport properties of the Janus GaInX 2 (X = S, Se, Te) monolayers by using the first-principles calculations. The stability of the investigated monolayers is confirmed via the analysis of vibrational spectrum and molecular dynamics simulations. Our calculations demonstrate that while GaInS2 and GaInSe2 monolayers are direct semiconductors, GaInTe2 monolayer exhibits the characteristics of an indirect semiconductor. The band gap of GaInX 2 decreases when the chalcogen element X varies from S to Te. Obtained results reveal that small spin–orbit splitting energy in the valence band is found around the Γ point of the Brillouin zone when the spin–orbit coupling is included. Interestingly, GaInS2 and GaInSe2 have high and directional isotropic electron mobility meanwhile the directional anisotropy of the electron mobility is found in the Janus GaInTe2 monolayer. Our findings not only present superior physical properties of GaInX 2 monolayers but also show promising potential applications of these materials in nanoelectronic devices.

Direct Electrosynthesis of Selective Transition-Metal Chalcogenides as Functional Catalysts with a Tunable Activity for Efficient Water Electrolysis

Transition-metal chalcogenides (TMCs) are cheap and abundant and have recently been demonstrated as promising electrocatalysts for sustainable and efficient water electrolysis. The existing TMC synthesizing methods are limited by difficulties in precise composition control and complexities in synthetic parameters, highlighting the need for a facile and viable strategy for direct synthesis of TMCs on conducting substrates. Here, we report a generalized approach for direct synthesis of a variety of high-efficient, robust TMCs and stoichiometric composition-controlled TMC catalysts on conducting three-dimensional porous substrates via an anion-assisted electrochemical deposition technique. Using this strategy, 10 different types of TMC electrocatalysts were designed and synthesized using representative transition-metal elements (Co, Fe, Mo, Ni, and W) and chalcogen elements (S and Se). In particular, NiS and FeSe exhibited excellent activity with overpotentials of 83 and 171 mV to reach a current density of 10 mA cm–2 in HER and OER, respectively. In addition, control over the stoichiometric composition was also demonstrated by adjusting the ratio of binary chalcogen anions, in turn allowing for the modification of catalytic properties. Furthermore, a water electrolysis cell with the NiS cathode and FeSe anode showed remarkable overall water splitting performance with a cell voltage of 1.52 V at 10 mA cm–2 and superior long-term stability for 100 h even at a high current density (100 mA cm–2), which was a significantly higher performance in comparison with the other reported TMC-based cells and the benchmark noble Pt/C∥IrO2 cell.

Conversion-Type Nonmetal Elemental Tellurium Anode with High Utilization for Mild/Alkaline Zinc Batteries.

Zinc ion batteries (ZIBs), generally established on an excessive metallic Zn anode and aqueous electrolytes, suffer from severe dendrites and gassing issues at Zn side, resulting in poor cycling life. Substituting Zn metal anode with non-Zn ones is a promising strategy for solving these problems, whereas this is still restricted by the limited anode alternatives. Herein, by replacing metal Zn with chalcogen element tellurium (Te), a conversion-type Te-based ZIB is reported that can work in both mild and alkaline electrolytes. As expected, the as-assembled mild Te/MnO2 and alkaline Te/Ni(OH)2 cells deliver remarkable capacities up to 106 and 161mAhg-1 anode+cathode , respectively, with a high utilization of anode (50.1% for the Te/MnO2 and 38.9% for the Te/Ni(OH)2 ), which surpass all ZIBs. Ultralong cycling life (over 75% capacity retention after 5000 cycles) is achieved in the two systems, benefiting from the stable conversion mechanisms (mild: Te to ZnTe2 to ZnTe; alkaline: ZnTe to Te to TeO2 ) with thoroughly eliminated dendrites and gassing. Moreover, high gravimetric energy density of ZIBs is also achieved, which are 176.3Whkg-1 anode+cathdoe (Te/Ni(OH)2 ) and 81WhKg-1 anode+cathode (Te/MnO2 ), respectively. This work sheds light on the development of advanced conversion-type anode for high-performance batteries with superior stability.

A theoretical study on elastic, electronic, transport, optical and thermoelectric properties of Janus SnSO monolayer

Janus structures have superior physical properties due to their vertical asymmetric structure. Although oxygen is a chalcogen element (group VI), recent studies on Janus structures as well as monochalcogenides or dichalcogenides have usually focused on the -phase of S, Se, and Te based compounds. In this study, we systematically investigate the structural, elastic, electronic, transport, optical, and thermoelectric properties of the Janus SnSO monolayer using density functional theory. The Janus SnSO monolayer is found to be stable through phonon spectrum analysis and dynamics simulations. Obtained results demonstrate that SnSO monolayer possesses fully isotropic elastic properties and is more flexible than other two-dimensional materials. In the ground state, the SnSO monolayer is a semiconductor with a direct bandgap whose electronic properties can be easily controlled by strain engineering or the electric field. The electron mobility of the SnSO monolayer is found to be 216.460 cm2 V−1 s−1, which is favorable for applications in nanoscale electronics. The optical properties of the SnSO monolayer are accurately examined via the plus the Bethe-Salpeter equation method. Our results reveal that SnSO has a wide absorption spectrum starting in the infrared and its maximum optical absorbance is up to cm−1 in the near-ultraviolet region. Finally, we investigate the thermoelectric properties of the SnSO monolayer via the semiclassical Boltzmann transport theory. The relaxation time at room temperature is found to be s. The doping level dependence of electronic transport coefficients of the SnSO monolayer is investigated in detail.

Surface Diffusion and Epitaxial Self-Planarization for Wafer-Scale Single-Grain Metal Chalcogenide Thin Films.

Although wafer-scale single-grain thin films of 2D metal chalcogenides (MCs) have been extensively sought after during the last decade, the grain size of the MC thin films is still limited in the sub-millimeter scale. A general strategy of synthesizing wafer-scale single-grain MC thin films by using commercial wafers (Si, Ge, GaAs) both as metal source and epitaxial collimator is presented. A new mechanism of single-grain thin-film formation, surface diffusion, and epitaxial self-planarization is proposed, where chalcogen elements migrate preferentially along substrate surface and the epitaxial crystal domains flow to form an atomically smooth thin film. Through synchrotron X-ray diffraction and high-resolution scanning transmission electron microscopy, the formation of single-grain Si2 Te3 , GeTe, GeSe, and GaTe thin films on (111) Si, Ge, and (100) GaAs is verified. The Si2 Te3 thin film is used to achieve transfer-free fabrication of a high-performance bipolar memristive electrical-switching device.

Hybrid density functional study of band gap engineering of SrTiO3 photocatalyst via doping for water splitting

Perovskite SrTiO3 (STO) is an attractive photocatalyst for solar water splitting, but suffers from a limited photoresponse in the ultraviolet spectral range due to its wide band gap. By means of hybrid density functional theory calculations, we systematically study engineering its band gap via doping 4d and 5d transition metals M (M=Zr, Nb, Mo, Tc, Ru, Rh, Pd, Hf, Ta, W, Re, Os, Ir and Pt) and chalcogen elements Y (Y=S and Se). We find that transition metal dopant M either has no effect on STO band gap or introduces detrimental mid-gap states, except for Pd and Pt that are able to reduce the STO band gap. In contrast, doping S and Se significantly reduces STO's direct band gap, thus leading to appreciable optical absorption transitions in the visible spectral range. Our findings provide that Pd, S and Se doped STO are potential promising photocatalysts for water splitting under visible light irradiation, thereby providing insightful theoretical guides for experiments to improve the photocatalytic activity of STO.

Role of rare earth on the spectral properties of chalcogenide glassy alloys: A review

In this paper, recent results regarding rare earth element doped with chalcogenide glasses for optical gain media such as amplifiers and lasers are reviewed. Rare earth Chalcogenide glasses are formed when chalcogen elements (S, Se, Te etc.) are mixed with new additive elements (Ge, Ga, Sb, As etc.) and also with rare earth elements (Er, Dy, Pd, Pr etc.) from periodic table and prepared by melt quench technique (MQT). Rare earth element doped with chalcogenide glasses has been emerged as a suitable candidate for applications in the numeral passive and active. Among various materials, chalcogenide glasses show significant improvement in their emission properties in the optical communication range and spectroscopic properties. Finally, rare earth doped chalcogenide and optical fibers show potential for high power mid-infrared gain medium and their spectroscopic properties as well.

Manufacturing of GLS-Se glass rods and structured preforms by extrusion for optical fiber drawing for the IR region

Chalcogenide glasses are amorphous solid materials formed from chalcogen elements bonding with metals to form typically in binary or tertiary compounds. One family of chalcogenide glasses, based on gallium and lanthanum sulphides, possesses properties important for the infrared (IR) window transmissions and IR applications; these include thermal stability, high solubility of rare earth ions, low phonon energy and high laser damage threshold. Efforts have been made to produce new chalcogenide glasses that can extend the IR transmission window further into the IR. Work has led to the successful melting of a selenium-modified gallium lanthanum sulphide (GLS-Se) glass that can transmit up to 15 μm, however these glasses have, to date, only been demonstrated in bulk glass form. We aim to develop processes for the fabrication of chalcogenide optical fiber to exploit the properties of chalcogenide glasses. Several potential applications include sensing for the civil, medical, and military areas, as these materials offer transmission over much of the molecular fingerprint region (2 to 25 μm). The aim of our work is to understand and control the thermal properties and stability of GLS-Se glasses without compromising their optical properties, in order to produce transparent glass rods and demonstrate the feasibility in fabrication for structured optical preforms by extrusion, as the first step to achieve optical fiber from GLS-Se glass.

Selenium-containing D−A−D-type dopant-free hole transport materials for perovskite solar cells

A novel selenium-containing D−A−D-type dopant-free hole-transport material with fused dithienobenzoselenadiazole acceptor unit (DTBS) was designed, synthesized and applied in a perovskite solar cell (PSC). In addition, two dopant-free hole-transport materials were prepared as references with similar structure but different chalcogen elements (O for DTBF and S for DTBT) being used. The impact of chalcogen atom variation in the dopant-free hole-transport materials on the properties is systematically investigated, such as the physicochemical, electrochemical, morphological feature and photovoltaic properties in PSC. The PSC fabricated with DTBS shows the power conversion efficiency value of 15.09% due to its high fill factor, which is much higher than those with the references (13.31% for DTBF and 11.65% for DTBT). Moreover, the PSCs fabricated with DTBS without encapsulation are operational with 77.8% performance retention under air condition after 30 days, which is much better than those prepared with doped spiro-OMeTAD (43.6%). The great stability for the DTBS-based PSC may be owing to the excellent thin film morphology and hydrophobicity of DTBS. Our work demonstrates that the selenium-containing organic compounds can act as the dopant-free hole-transport materials in PSC with both high efficiency and long stability being achieved.

Sticking coefficients of selenium and tellurium

The sticking coefficients of selenium and tellurium were measured as a function of temperature. Molecular beams of the chalcogen elements supplied from thermal effusion cells were directed onto a heated quartz crystal microbalance, and the mass gain rate was detected as a function of temperature. Both sticking coefficients were found to sharply drop within a narrow temperature range of 20 and 30 °C from above 0.8 down to about 0.2 at film surface temperatures around 35 and 115 °C for selenium and tellurium, respectively. While the sticking coefficient of tellurium reached zero at temperatures above 150 °C, the sticking coefficient of selenium remained about 0.2 up to a film surface temperature of 60 °C, suggesting that selenium was supplied in different chemical forms. The direct and quantitative determination of the sticking coefficients provides important insights into the kinetics of chalcogenide-based film growth and points toward the need of a precise sample temperature control.