DE202022104505U1 - A system for synthesizing Se50-XTe30Sn20Sbx chalcogenide glass - Google Patents

Abstract

A system (100) for synthesizing Se ₅₀ -xTe ₃₀ Sn ₂₀ Sb _x chalcogenide glass, the system (100) comprising:
a mixing chamber (102) for adding a stoichiometric amount of a plurality of compounds such as selenium (Se), tellurium (Te), antimony (Sb) and tin (Sn);
a mill (104) connected to an agate mortar (106) for grinding the plurality of compounds at room temperature after mixing to obtain a homogenized mixture;
a furnace (108) connected to a vacuum quartz ampoule (110) for heating the homogenized mixture to a defined temperature in multiple stages, the first stage heating the homogenized mixture to a first temperature lower than the defined temperature wherein in the second stage the homogenized mixture is heated to a second temperature higher than the first temperature to reach the defined temperature; and
a rotation module (112) connected to the furnace (108) for rotating the ampoule for uniform heating to obtain the homogeneous chalcogenide glass.

Description

FIELD OF THE INVENTION

The present invention relates to the field of synthesis of glassy systems. In particular, the present invention relates to a system for synthesizing chalcogenide glass.

BACKGROUND OF THE INVENTION

The most intriguing material in this field are the third-generation quaternary chalcogenide semiconductor quantum dots, whose physical, structural, optical and electronic properties can be manipulated by changing their stoichiometric composition. In chalcogenide alloys, one or more chalcogen elements like Se, S, Te are covalently linked with elements like Sn, Sb, Bi, Ge etc., which are interesting because of their special properties like low phonon energy, excellent transmittance, higher linear and nonlinear refractive index Alloys result that are suitable for use in photonic devices, IR sensors, waveguides, optical switches, etc.

Conventionally, the selenium-doped chalcogenide glasses are considered worldwide, although pure Se is not a suitable glass former and due to its low thermal stability, low photosensitivity and short lifetime, it lacks practical applications and is less feasible.

In order to overcome the above problems, an additional element such as Te is added to Se, which brings higher photosensitivity, better thermal stability and shorter aging effects. When Te is added to Se, Te cleaves the Se8 ring structure and acts as a bond modifier, attaching to the Se chain structure through crosslinking; this change is responsible for increasing the glass transition temperature. This material is commonly used for xerographic and electrographic applications, but has some disadvantages when used in phase change memory devices.

This limitation is due to the low crystallization temperature, which is overcome by incorporating a metallic dopant such as Sn into the Se-Te matrix, which increases thermal stability. Incorporation of a metallic dopant such as Sn into the Se-Te host matrix shifts the Fermi level towards one of the bands due to the structural change, altering the electrical and optical properties of the glassy network.

The incorporation of metal elements opens up many different fields of application, and the Se-Te alloys become multifunctional. The underprivileged thermo-electric properties of Se-Te alloys are later enhanced by the incorporation of an additional metallic element Sb, which extends the range of glass formation and introduces structural disorder that increases the potential for device applications.

US7330634B2 discloses low viscosity chalcogenide glass for extrusion and injection molding having the general formula YZ, where Y is Ge, As, Sb, or a mixture of two or more thereof; Z is Se, Te or a mixture of Se+Te; and Y and Z are present in amounts (in atomic/element percent) ranging from Y=15-70% and Z=30-85%.

The above prior art discloses chalcogenide glass containing Se+Te and either Ge, As or Sb.

However, none of the above prior arts disclose a quaternary system which acts as a network modifier and has a high crystallization free energy value.

Therefore, there is a need to develop a Se-Te-Sn-Sb quaternary system in which the metalloid Sb acts as a network modifier and improves the durability of some devices such as batteries and sensors due to a higher crystallization free energy value.

The technical advance disclosed by the present invention overcomes the limitations and disadvantages of existing and conventional systems and methods.

SUMMARY OF THE INVENTION

The present invention relates generally to a system for synthesizing Se ₅₀ -XTe ₃₀ Sn ₂₀ Sb _x chalcogenide glass.

The aim of the present invention is to develop a system for the synthesis of Se ₅₀ -XTe ₃₀ Sn ₂₀ Sb _x -chalcogenide glass,
Another object of the present invention is to improve the durability of some devices such as batteries and sensors,
Another object of the present invention is to achieve a higher value for the free energy of crystallization,
Another aim of the present invention is to study the compositional dependence of various physical, structural and optical parameters in terms of percolation theory, and
Another object of the present invention is to study the tuning of the band gap and the shift of the CB and VB potential with a slight change in the Sb value (x) of the metal element.

• eine Mischkammer zur Zugabe einer stöchiometrischen Menge einer Vielzahl von Verbindungen wie Selen (Se), Tellur (Te), Antimon (Sb) und Zinn (Sn);
• eine Mühle, die mit einem Achatmörser verbunden ist, um die Vielzahl von Verbindungen bei Raumtemperatur nach dem Mischen zu mahlen, um eine homogenisierte Mischung zu erhalten;
• einen mit einer Vakuum-Quarz-Ampulle verbundenen Ofen zum Erhitzen der homogenisierten Mischung auf eine definierte Temperatur in mehreren Stufen, wobei in der ersten Stufe die homogenisierte Mischung auf eine erste Temperatur unterhalb der definierten Temperatur erhitzt wird, wobei in der zweiten Stufe die homogenisierte Mischung auf eine zweite Temperatur oberhalb der ersten Temperatur erhitzt wird, um die definierte Temperatur zu erreichen; und
• ein mit dem Ofen verbundenes Drehmodul zum Drehen der Ampulle für eine gleichmäßige Erwärmung, um das homogene Chalkogenidglas zu erhalten.

In one embodiment, a system for synthesizing Se ₅₀ -XTe ₃₀ Sn ₂₀ Sb _x chalcogenide glass, the system comprising:

• a mixing chamber for adding a stoichiometric amount of a variety of compounds such as selenium (Se), tellurium (Te), antimony (Sb), and tin (Sn);
• a mill connected to an agate mortar to grind the plurality of compounds at room temperature after mixing to obtain a homogenized mixture;
• a furnace connected to a vacuum quartz ampoule for heating the homogenized mixture to a defined temperature in several stages, in the first stage the homogenized mixture is heated to a first temperature below the defined temperature, in the second stage the homogenized mixture is heated heating to a second temperature above the first temperature to reach the defined temperature; and
• a rotary module connected to the furnace to rotate the ampoule for uniform heating to obtain the homogeneous chalcogenide glass.

In one embodiment, the agate mortar is connected to the mixing chamber for mixing the stoichiometric amount of the multiple compounds.

In one embodiment, a roller mill homogenizes the milled mixture for about 30-90 minutes to obtain the homogenized mixture.

In one embodiment, the vacuum quartz ampoule is connected to the roller mix to seal the homogenized mix.

In one embodiment, the chemical composition of the Se ₅₀ -xTe ₃₀ Sn ₂₀ Sb _x chalcogenide glass has a value of x=2, 4, 6 and 8.

In one embodiment, the desired temperature is 1000°C, with the first stage increasing the first temperature to 700°C, the second stage increasing the second temperature from 700°C to 1000°C at a heating rate of 4° deg/ minutes is increased.

In one embodiment, the homogenized mixture is heated to the desired temperature for about 7-9 hours.

In one embodiment, the heated homogenized mixture is chilled with cold water, preferably ice water, to form a quartz ampoule.

In one embodiment, the quartz ampoule is reduced to a fine powder, preferably micron size, by grinding with a grinder.

In order to further clarify the advantages and features of the present invention, a more detailed description of the invention will be provided by reference to specific embodiments thereof, which are illustrated in shown in the accompanying figures. It is understood that these figures represent only typical embodiments of the invention and therefore should not be considered as limiting its scope. The invention will be described and illustrated with additional specificity and detail with the accompanying figures.

character list

• 1 zeigt ein Blockdiagramm eines Systems zur Synthese von Se₅₀-XTe₃₀Sn ₂₀Sb_x-Chalkogenidglas,
• 2 zeigt eine grafische Darstellung der XRD-Muster aller glasartigen Chalkogenidsysteme,
• 3a und 3b zeigen eine grafische Darstellung der Variation der Dichte und des molaren Volumens aller Proben,
• 4a, 4b und 4c zeigen eine grafische Darstellung von (a) Molmasse, (b) Kompaktheit und (c) FVP in Abhängigkeit vom prozentualen Sb-Gehalt (x),
• 5a und 5b zeigen eine grafische Darstellung der Variation von (a) Polaronradius und (b) Feldstärke in Abhängigkeit vom prozentualen Sb-Gehalt (x),
• 6a und 6b zeigen eine grafische Darstellung von (αhv) 0,5 gegen (hv) und (b) die Veränderung von Eg gegen den Prozentsatz des Sb-Gehalts (x),
• 7 zeigt eine grafische Darstellung des Trends der theoretisch und experimentell ermittelten Bandlückenenergiewerte für alle Proben,
• 8 zeigt eine grafische Darstellung der Variation der Elektronegativität in Abhängigkeit vom prozentualen Sb-Gehalt (x),
• 9 zeigt eine grafische Darstellung der CB- und VB-Positionen von Se₅₀-xTe₃₀Sn₂₀Sb_x Chalkogenid-Glassystemen,
• 10 zeigt eine grafische Darstellung der Variation der Floppy-Modi und der Vernetzungsdichte in Abhängigkeit vom prozentualen Sb-Gehalt,
• 11a und 11b zeigen eine grafische Darstellung der Variation des Parameters des einsamen Paarelektrons (L) und des Parameters R in Bezug auf den prozentualen Sb-Gehalt (x), und
• 12a und 12b zeigen eine grafische Darstellung der Variation von (a) mittlerer Bindungsenergie <E> und (b) Glasübergangstemperatur. (Tg) gegen den Prozentsatz des Sb-Gehalts (x).

These and other features, aspects and advantages of the present invention will be better understood when the following detailed description is read with reference to the accompanying figures, in which like characters represent like parts throughout the figures, wherein:

• 1 shows a block diagram of a system for the synthesis of Se ₅₀ -XTe ₃₀ Sn ₂₀ Sb _x -chalcogenide glass,
• 2 shows a graphical representation of the XRD patterns of all glassy chalcogenide systems,
• 3a and 3b show a graphical representation of the variation in density and molar volume of all samples,
• 4a , 4b and 4c show a graphical representation of (a) molar mass, (b) compactness and (c) FVP as a function of percentage Sb content (x),
• 5a and 5b show a graphical representation of the variation of (a) polaron radius and (b) field strength as a function of percentage Sb content (x),
• 6a and 6b show a plot of (αhv) 0.5 versus (hv) and (b) the change in Eg versus percentage of Sb content (x),
• 7 shows a graphical representation of the trend of theoretically and experimentally determined band gap energy values for all samples,
• 8th shows a graphical representation of the variation of electronegativity as a function of percentage Sb content (x),
• 9 shows a plot of the CB and VB positions of Se ₅₀ -xTe ₃₀ Sn ₂₀ Sb _x chalcogenide glass systems,
• 10 shows a graphical representation of the variation of floppy modes and crosslink density as a function of percentage Sb content,
• 11a and 11b show a graphical representation of the variation of the parameter of the lone pair electron (L) and the parameter R with respect to the percentage Sb content (x), and
• 12a and 12b show a graphical representation of the variation of (a) mean binding energy <E> and (b) glass transition temperature. (Tg) versus percentage of Sb content (x).

Those skilled in the art will understand that the elements in the figures are presented for simplicity and are not necessarily drawn to scale. For example, the flow charts illustrate the method of key steps to enhance understanding of aspects of the present disclosure. In addition, one or more components of the device may be represented in the figures by conventional symbols, and the figures only show the specific details relevant to understanding the embodiments of the present disclosure, not to encircle the figures with details to overload, which are easily recognizable to those skilled in the art familiar with the present description.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the invention, reference will now be made to the embodiment illustrated in the figures and specific language will be used to describe the same. It should be understood, however, that no limitation on the scope of the invention is intended, and such alterations and further modifications to the illustrated system and such further applications of the principles of the invention set forth therein are contemplated as would occur to those skilled in the art invention would normally come to mind.

Those skilled in the art will understand that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be limiting.

When this specification refers to "an aspect,""anotheraspect," or the like, it means that a particular feature, structure, or characteristic described in connection with the embodiment is present in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment,""in another embodiment," and similar phrases throughout this specification may or may not all refer to the same embodiment.

The terms "comprises," "including," or other variations thereof are intended to cover non-exclusive inclusion, such that a method or method that includes a list of steps includes not only those steps, but may also include other steps that are not expressly stated or pertaining to any such process or method. Likewise, any device or subsystem or element or structure or component preceded by "comprises...a" does not, without further limitation, exclude the existence of other devices or other subsystem or other element or other structure or other component or additional device or additional subsystems or additional elements or additional structures or additional components.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one skilled in the art to which this invention pertains. The system, methods, and examples provided herein are for purposes of illustration only and are not intended to be limiting.

Embodiments of the present invention are described in detail below with reference to the attached figures.

1 Figure 12 shows a block diagram of a system (100) for synthesizing Se ₅₀ -XTe ₃₀ Sn ₂₀ Sb _x chalcogenide glass, the system (100) comprising: a mixing chamber (102), a mill (104), an agate mortar (106), an oven (108), a vacuum quartz ampoule (110), a rotary module (112), and a roller blender (114).

The mixing chamber (102) for adding a stoichiometric amount of a variety of compounds such as selenium (Se), tellurium (Te), antimony (Sb) and tin (Sn). The mixing chamber is preferably a container or beaker. The chemical composition of the Se ₅₀ -xTe ₃₀ Sn ₂₀ Sb _x chalcogenide glass has a value of x = 2, 4, 6 and 8.

The grinder (104) is connected to an agate mortar (106) to crush the plurality of compounds at room temperature after mixing to obtain a homogenized mixture. The agate mortar (106) is connected to the mixing chamber (102) for mixing the stoichiometric amount of the plurality of compounds.

A vacuum quartz ampoule (110) is associated with the furnace (108) to heat the homogenized mixture to a defined temperature in several stages, wherein in the first stage the homogenized mixture is heated to a first temperature lower than that defined temperature, wherein in the second stage the homogenized mixture is heated to a second temperature, which is higher than the first temperature, in order to reach the defined temperature. The vacuum quartz ampoule (110) is connected to the roller mix (114) to seal the homogenized mix. The homogenized mixture is heated to the desired temperature for about 7-9 hours.

The desired temperature is 1000°C, with the first stage increasing the first temperature to 700°C, the second stage increasing the second temperature from 700°C to 1000°C at a heating rate of 4 degrees/min .

The rotating module (112) is connected to the furnace (108) to rotate the ampoule for uniform heating and thus obtain a homogeneous chalcogenide glass.

The roller mixer (114) homogenizes the milled mixture for about 30-90 minutes to obtain the homogenized mixture.

The heated homogenized mixture is quenched with cold water, preferably ice water, to form a quartz ampoule. The quartz ampoule is broken into fine powder, preferably micron size, by crushing with grinder (104).

X-ray diffraction analysis (XRD) was performed at room temperature with an X-ray diffractometer using CuKa radiation of 1.5418 A _° with scan angles 20 ranging from 5 _° to 80 _° and changes at a uniform scan speed of 20/min with a step size of 0.02 _° , to study the structural features of the chalcogenide systems. With these specifications, the diffractometer is able to identify the possible diffraction lines.

To perform the UV-Vis absorption method, ethyl alcohol is used to absorb the driven chalcogenide glass samples to produce the colloidal homogeneous suspension. For the UV absorption measurement, the spectrometer is used in the wavelength range of 200-800 nm at room temperature.

The theoretical value of density (ρ) is calculated using the following relationship: ρ = Σ(x _i /d _i ) ^-1

Here, xi stands for the weight fraction, di for the density of the i-th component. The molar mass (M) of the system is calculated using the following equation: M=Σ _i X _i A _i

The molar volume (Vm) results from knowledge of the density (ρ) and the molar mass (M). It follows from the relationship given below: $$\text{Vm}=\text{i}/\mathrm{\rho }{\displaystyle {\sum }_i{X}_{\text{i}}{\text{M}}_{\text{i}}}$$

wobei sich ρ_aceton auf die Dichte der nichtlösenden Flüssigkeit Aceton bezieht, W_Luft das an der Luft gemessene Gewicht der Probe und W_aceton auf das Gewicht der Probe in Aceton bezieht.where Mi represents the molecular weight of the i-th component and xi represents the atomic percentage of the sample. The famous Archimedis principle is used to measure the density and molar volume of the bulk chalcogenide sample by using the following relationship: $$\mathrm{\rho }={\mathrm{\rho }}_{\text{acetone}}\left({\text{W}}_{\text{Air}}/{\text{W}}_{\text{Air}}-{\text{W}}_{\text{acetone}}\right)$$

where ρ _acetone refers to the density of the non-solvent liquid acetone, W _air refers to the weight of the sample measured in air, and W _acetone refers to the weight of the sample in acetone.

The compactness (δ) is related to the free volume and flexibility of the mesh. It indicates the amount of the normalized change in the mean atomic volume due to the mutual chemical interactions of the network-forming elements. The compactness is evaluated considering the atomic fraction, the atomic weight of the i-th constitution and the atomic density of the i-th component.

2 shows a graphical representation of the XRD patterns of all glassy chalcogenide systems.

The plot shows no prominent peak in the XRD pattern, reflecting the amorphous nature of the glassy alloys, as noted by other investigators. The amorphous halo peak at around 30 _° is prominent in all compositions due to diffraction of the orthorhombic Sb ₂ Se ₃ phase.

3a and 3b show a graphical representation of the variation in density and molar volume of all samples.

It is extremely important to determine the density values in order to examine the various structural and microstructural parameters of the prepared samples. The density values of the individual components listed in Table 1 together with some other physical parameters were used to evaluate the theoretical density values of the various compositions. parameter se Te sn Sb CN 2 2 4 3 H _s (kcal/mol) 54.30 46 72.20 62.67 electronegativity 2.55 2.10 1.88 2.05 BE (Kcal/mole) 44.0 33 34.2 30.2 P (gcm ^-3 ) 4.81 6.24 7.31 6.69 Eg(ev) 1.95 0.335 0 0.101

The density reflects the rigidity of the system. Any change in the density value indicates structural anomalies within the glassy network. Both the molar mass (Mm) (a) and molar volume (Vm) values follow a similar trend as both parameters increase linearly with increasing percentage of Sb content (x). From the molar volume (Vm) and molar mass (Mm) graph, the linear equations are calculated showing the relationship between the Vm values and the Mm values with the variation of the Sb content represented by the following relationships will: $$\text{Vm}=18.25+0.014\text{x and Mm}=101.50+0.428\text{x}$$

Density values should be inversely proportional to molar volume. However, opposite results were obtained. This discrepancy arises because the rate of change of molar mass (Mm) is higher than that of density, which in turn increases the molar volume (Vm) with increasing Sb content (x). The following empirical relationship is derived to evaluate the value of compactness (δ). $$\mathrm{\delta }=\left(\left(17.6258+0.0173\text{x}\right)/\text{Vm}\right)-1$$

It is found that the evaluated value of δ becomes less negative, i.e. it progressively increases with the addition of the Sb content (x). The gradual increase in the compactness value means that the system evolves from a slack to a rigid network and mechanical stability is gradually reached, which can also be correlated with the calculated average coordination number <Z>. From the concept of percolation theory it is known that at a threshold of <Z> = 2.40 the glassy system changes from a slack to a rigid network. As the value of <Z> gradually increases beyond 2.40, the stiffness of the glassy network also increases.

the 4a , 4b and 4c show a plot of (a) molar mass, (b) compactness, and (c) FVP versus percentage Sb content (x).

The linearly increasing trend in compactness (δ) confirms the presence of a fraction of free volume (FVP) in the samples examined. Therefore it is necessary to determine the percentage of free volume in the glassy system. It can be observed that the determined FVP values gradually decrease from 3.41 to 3.29 with increasing Sb content (x). Packing density (PD) is also an important parameter for structural studies. In a vitreous network, the packing density indicates the ratio between the space used and the space allocated. The value of the PD can be derived and decreases linearly with increasing Sb content (x).

5a and 5b show a graphical representation of the variation of (a) polaron radius and (b) field strength as a function of percentage Sb content (x).

To better understand the interactions between electrons and atoms in an ordered or disordered material, the concept of the polaron is introduced. In a semiconductor, the generation of polarons decreases the mobility of electrons within the material. It is therefore important for the structural investigation to obtain information about the size of the polaron that forms in the system. The value of the NAD parameter is determined using the Naster-Kingery formula.

The field strength amplifies the Se field, which affects the other atoms present in the system. The value of the field strength gradually decreases from 9,226 × 1015 cm ^-2 to 8,554 × 1015 cm ^-2 . The reason for the decrease in field strength could be the increase in average distance. The value of the polaron radius increases while the values of the field strength decrease as the atomic density decreases. This result indicates an increase in the compactness of the system and a subsequent decrease in the fraction of free volume.

6a and 6b shows a plot of (αhv) 0.5 versus (hv) and (b) the change in Eg versus percentage of Sb content (x).

The value of the optical band gap energy (Eg) can be determined using the Davis-Mott relationship: $$\mathrm{a}\left(\text{H}\mathrm{\upsilon }\right)={\left[\text{A}\left(\text{H}\mathrm{\upsilon }-\text{eg}\right)\right]}^{\text{n}}$$

The energy of the incident photons is denoted by hv, and A is the end-of-band parameter. In the above expression, n refers to the type of transition with the values 1/2, 2, 3/2, and 3 denoting direct allowed transition, indirect allowed transition, direct forbidden transition, and indirect forbidden transition, respectively. The energy gap between the conduction band and the valence band is called the optical band gap and is represented as Eg. A plot of (ahv)0.5 versus photon energy (hv) is known as a Tauc plot, which is drawn with the indirect transition taken into account.

To obtain the values of Eg, the linear parts of the curves on the X-axis are extrapolated to (ahv)0.5 = 0. The optical band gap energy values of the examined sample decrease from 1,264 eV to 1,216 eV with the Sb content (x).

Being a charged species, the incorporation of Sb into the glassy network alters the population of “valency change pairs” and modifies the band gap. In addition, the reduction in optical bandgap energy is attributed to the reduction in cohesion energy, which is consistent with the cohesion energy values obtained.

The band gap energy can also be determined theoretically using the Shimakawa relation (see below): $${\text{E}}^{\text{th}}{}_{\text{G}}=\mathrm{a}{\text{E}}_{\text{G}}\left(\text{se}\right)+\mathrm{\beta }{\text{E}}_{\text{G}}\left(\text{Te}\right)+\mathrm{g}{\text{E}}_{\text{G}}\left(\text{sn}\right)+\mathrm{\delta }{\text{E}}_{\text{G}}\left(\text{Sb}\right)$$

7 shows a graphical representation of the trend of theoretically and experimentally determined band gap energy values for all samples.

The volume fraction of each atom is represented by the parameters α, β, γ and δ. The values of the theoretical band gap energy can be determined using the values of the individual band gaps listed in Table 1. The theoretical band gap energies are calculated using the Shimakawa relationship. It is observed that the theoretically estimated band gap energy values also follow a similar trend as the experimentally determined values, and the band gap energy values decrease from 1.18 eV to 1.08 eV. The decrease in band gap energy is due to the decrease in the overall electronegativity of the system.

8th shows a graphical representation of the variation of electronegativity as a function of the percentage Sb content (x).

The obtained electronegativity values of all samples decrease from 2.27 to 2.24 with increasing amount of Sb(x). Replacing a more electronegative Se atom with a less electronegative Sb atom leads to a decrease in the average electronegativity value of the system. This reduction in electronegativity is due to the reduction in the band gap energy of the system. Optical parameters can also be examined using the transmittance (T) and reflectance (R) versus wavelength plots.

9 shows a plot of the CB and VB positions of Se ₅₀ -xTe ₃₀ Sn ₂₀ Sb _x chalcogenide glass systems.

A band diagram showing the edges of the conduction band and valence band. The diagram shows that the position of the conduction band and the valence band gradually shift towards each other, leading to a reduction in the band gap in the composition. Thus, the incorporation of Sb(x) into the glass matrix leads to a decrease in the band gap, and the sample has a band gap energy value im infrared range. The investigated composites are therefore suitable for applications such as near-infrared microscopy detectors and are a promising candidate for solar cells.

10 Figure 12 shows a graphical representation of the variation of floppy modes and crosslink density as a function of percentage Sb content.

The fraction of the floppy modes (f) is an important parameter for studying the glass matrix. The value of f approaches zero at the critical value of <Z> = 2.4. Glass networks with a value of <Z> less than 2.4 are referred to as polymeric glasses with a floppy network. On the other hand, if the value of <Z> is greater than 2.4, it is an amorphous solid or rigid glass network. The proportion of floppy modes (f) can be determined by: $$\text{f}=2-\frac{5<\text{e.g}>}{6}$$

The values of f show that the value of f tends to zero as the value of <Z> approaches 2.4. As the Sb content increases, the fraction of the floppy modes (f) becomes more and more negative since the system stiffness increases step by step with the Sb content (x). The crosslink density of the examined sample can be determined by the following relationship: $${\text{D}}_{\text{CL}}={\text{N}}_{\text{CO}}-2$$

As the stiffness of the mesh gradually decreases, the estimated value of the crosslink density (DCL) also decreases as the average coordination number (<Z>) decreases. It was found that the crosslink density of the investigated system is linearly correlated with the increasing Sb content (x).

11a and 11b show a graphical representation of the variation of the lone pair parameter (L) and the parameter R as a function of the percentage Sb content (x).

Calculation of the lone pair of electrons (L) confirms the degree of glass-forming ability. The estimated value for the number of lone electron pairs (L) is found by the following relationship. $$\text{L}=\text{V}-<\text{Z}>$$

where V refers to the valence electron. It can be observed that the values of L are higher than 3, confirming the good glass-forming ability of the components. In general, the value of L is greater than 1 for the ternary system and greater than 2.6 for the binary system. The high value of the lone pair of electrons (L) indicates the flexibility of the composition, which is required for optoelectronic applications. It can therefore be used as an optoelectronic component such as LEDs or photovoltaic diodes.

The deviation from stoichiometry is examined by a parameter called R. To understand the rigidity of the network, the mean binding energy needs to be determined, and for the proper derivation of the mean binding energy, it is essential to estimate the deviation from stoichiometry. The ratio of the covalent bonds of the chalcogen atoms to the non-chalcogen atoms present in the sample determines the parameter R. The system is considered chalcogen-rich if R > 1. If R < 1, the system is said to be low in chalcogen. The determined values of R increase with increasing Sb content (x) from 1.53 to 1.63, indicating a chalcogen-rich system.

12a and 12b show a graphical representation of the variation of (a) mean binding energy <E> and (b) glass transition temperature. (Tg) versus percentage of Sb content (x).

The value of <E> progressively increases with increasing Sb content (x), indicating the increase in glass stiffness with Sb content (x). The glass transition temperature is an important property for characterizing the glassy state. The mean binding energy is theoretically used to determine the glass transition temperature (Tg) using the following relationship: $$\text{day}=311\left(<\text{E}>-0.9\right)$$

It can be observed that as the Sb content (x) increases, the glass transition temperature (Tg) increases. The compositional variation of the glass transition temperature is studied with the Tichy-Tacha approach.

The glassy chalcogenide systems of composition Se ₅₀ -xTe ₃₀ Sn ₂₀ Sb _x (x = 2, 4, 6 and 8) have been successfully synthesized using the melt quenching technique. The physical, structural and optical parameters show a significant dependence on the composition. The chalcogenide systems become more dense with increasing Sb content (x), leading to an increase in compactness and a decrease in the packing density of the glassy system. The lone pair electron values decrease with increasing Sb content (x) and have a minimum value of 3.04, which is much larger than 1, indicating that the system studied has good glass-forming ability. The negative values of the floppy modes confirm the rigidity of the glassy system, which is confirmed by the increase in the mean binding energy. The parameter R > 1 shows that the investigated composition is a chalcogen-rich system. The theoretical and experimental values of the band gap energy decrease with increasing Sb content as the total electronegativity value of the system decreases. The obtained band gap energy values indicate the potential of the investigated glassy chalcogenide system as a candidate for application in infrared sensors. In addition, the bandgap energy range achieved makes the glassy system suitable for use in solar cell devices. Both the transmission and the reflection spectra are in the spectral range 200-800 nm and it can be observed that all samples have a high transmission at wavelengths above 380 nm. The increase in linear refractive index with increasing Sb content makes the system favorable for optical fiber fabrication. These results indicate that the investigated system can be used for the development of a new generation of optoelectronic devices.

The figures and the preceding description give examples of embodiments. Those skilled in the art will understand that one or more of the elements described may well be combined into a single functional element. Alternatively, certain elements can be broken down into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, the order of the processes described herein may be changed and is not limited to the manner described herein. Additionally, the actions of a flowchart need not be performed in the order shown; Also, not all actions have to be carried out. Also, those actions that are not dependent on other actions can be performed in parallel with the other actions. The scope of the embodiments is in no way limited by these specific examples. Numerous variations are possible, regardless of whether they are explicitly mentioned in the description or not, e.g. B. Differences in structure, dimensions and use of materials. The scope of the embodiments is at least as broad as indicated in the following claims.

Advantages, other benefits, and solutions to problems have been described above with respect to particular embodiments. However, the benefits, advantages, problem solutions, and components that can cause an advantage, benefit, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or component of any or all claims.

Reference List

100

A system for synthesizing Se _50-x Te ₃₀ Sn ₂₀ Sb _x chalcogenide glass

102

mixing chamber

104

Mill

106

agate grout

108

furnace

110

Vacuum Quartz Ampoule

112

Rotating module

114

roller mixer

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• US 7330634 B2 [0007]

Claims (9)

A system (100) for synthesizing Se ₅₀ -xTe ₃₀ Sn ₂₀ Sb _x chalcogenide glass, the system (100) comprising: a mixing chamber (102) for adding a stoichiometric amount of a plurality of compounds such as selenium (Se), tellurium ( Te), antimony (Sb) and tin (Sn); a mill (104) connected to an agate mortar (106) for grinding the plurality of compounds at room temperature after mixing to obtain a homogenized mixture; a furnace (108) connected to a vacuum quartz ampoule (110) for heating the homogenized mixture to a defined temperature in multiple stages, the first stage heating the homogenized mixture to a first temperature lower than the defined temperature wherein in the second stage the homogenized mixture is heated to a second temperature higher than the first temperature to reach the defined temperature; and a rotation module (112) connected to the furnace (108) for rotating the ampoule for uniform heating to obtain the homogeneous chalcogenide glass. system after claim 1 wherein the agate mortar (106) is connected to the mixing chamber (102) for mixing the stoichiometric amount of the plurality of compounds. system after claim 1 wherein a roller mixer (114) homogenizes the milled mixture for about 30-90 minutes to obtain the homogenized mixture. system after claim 1 wherein the vacuum quartz ampoule (110) is connected to the roller mix (114) to seal the homogenized mix. system after claim 1 , where the chemical composition of the Se ₅₀ -xTe ₃₀ Sn ₂₀ Sb _x chalcogenide glass has a value of x = 2, 4, 6 and 8. system after claim 1 , wherein the desired temperature is 1000°C, in the first stage the first temperature is increased to 700°C, in the second stage the second temperature is increased from 700°C to 1000°C with a heating rate of 4°deg/min is increased. system after claim 1 , heating the homogenized mixture to the desired temperature for about 7-9 hours. system after claim 1 wherein the heated homogenized mixture is quenched with cold water, preferably ice water, to form a quartz ampoule. system after claim 1 , in which the quartz ampoule is broken into a fine powder of preferably micrometer size by crushing with the grinder (104).

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