- Email: [email protected]
Influence of temperature on optical spectra of SbSI photonic crystals
Optical Materials 100 (2020) 109606
Contents lists available at ScienceDirect
Optical Materials journal homepage: http://www.elsevier.com/locate/optmat
Influence of temperature on optical spectra of SbSI photonic crystals � ska, Piotr Szperlich, Piotr Duka, Marian Nowak Anna Starczewska *, Mirosława Kępin Institute of Physics – Center for Science and Education, Silesian University of Technology, Krasi� nskiego 8, 40-019, Katowice, Poland
A R T I C L E I N F O
A B S T R A C T
Keywords: Photonic crystals Inverse opal Optical spectroscopy Antimony sulfoiodide
This work is focused on optical investigations of polycrystalline SbSI photonic crystals. SbSI inverse opals of sphere sizes 264 nm, 326 nm, and 464 nm were prepared. The reflectance spectra were measured for normal incidence of light on (111) surface for the light of range 350–1000 nm. The influence of temperature on reflectance spectra was investigated. The peaks associated with photonic band structure were registered. The results were analysed for the effects of temperature, refractive index, thermal expansion, as well as SbSI elec tronic energy gap (Eg) responsible for the existence of specific effects related to slow photons.
1. Introduction
methods of spherical colloids, e.g. by sedimentation in a gravitational field [13–15] or vertical deposition [2–4,19]. It should be emphasized that this is the simplest and the cheapest template production method that does not require expensive equipment. Simultaneously obtained layers have relatively good quality and a large surface. The use of or dered spheres in the size from several hundred nanometers to several micrometers results in a gap for electromagnetic waves in the visible and near-infrared range. Recently, SbSI photonic crystals with an inverse opal structure have been produced [13–15]. It should be emphasized that SbSI has an electronic band gap (Eg) of 1.9–2.0 eV [8] which cor responds to the visible range of light. In this work, the influence of Eg on the optical spectra of SbSI inverse opals with different sphere sizes and for various temperatures is presented.
The development of new technologies creates the possibility of producing various micro- and nanostructures from known materials, which have different properties compared to bulk materials. Photonic crystals (PC) are one of the most interesting optical structures because of their features. PC are characterized by a periodically variable refractive index, which leads to the appearance of interference effects and, as a consequence, photonic band gaps (PBGs) in the photonic band structure [1]. The range of wavelengths for which PBGs are observed depends on the lattice constant of structure. Other interesting effects can also be observed in PC structures. The latest published studies have been focused on slow photon phenomena [2–7]. Slow photons appear on the edges of PBG and increase light absorption when edges of PBG coinci dence the electronic band gap. This property is useful especially in various types of light-induced phenomena, such as photoconductivity or photocatalysis. Antimony sulphoiodide (SbSI) is one of the most intensively studied photoferroelectric semiconductor in recent years [8–18] because of many interesting properties, e.g.: photovoltaic, pyroelectric, piezoelec tric, pyro-optic, electrooptic, and other nonlinear optical effects. Furthermore, SbSI has relatively high refractive index (na ¼ 2,87, nb ¼ 3, 63 and nc ¼ 4,55 for λ ¼ 633 nm depending on crystallographic direction [11]), which makes it useful material for PC. Therefore SbSI has been used for theoretical modeling of 1D photonic crystals [11,12]. In the case of three-dimensional photonic crystals, various structures are pro posed in the literature: Yablonowite, woodpile or inverse opals [1]. The latter found special interest. They can be obtained using self-assembly
2. Experiment The fabrication of SbSI inverse opal structure involves several steps: synthesis of monosized silica (SiO2) spheres, packing the spheres into opal structure based on self-assembly, infiltration of the voids in opal with SbSI and etching the silica spheres. The details of SbSI inverse opals production were presented in Ref. [15]. The process of infiltration consists of keeping a SiO2 matrix in melted SbSI (in temperature 778 K) under low pressure and then cooling with the rate of 5 K/h. Slow cooling ensures obtaining SbSI in the polycrystalline form which was confirmed by XRD and Raman spectroscopy [15]. Using this procedure, three samples (A, B and C) of SbSI inverse opals for different sphere size were made. Morphology of the produced photonic crystals was characterized using the Phenom ProX desk scanning electron microscope (SEM).
* Corresponding author. E-mail address: [email protected] (A. Starczewska). https://doi.org/10.1016/j.optmat.2019.109606 Received 5 August 2019; Received in revised form 4 December 2019; Accepted 5 December 2019 Available online 18 December 2019 0925-3467/© 2019 Elsevier B.V. All rights reserved.
A. Starczewska et al.
Optical Materials 100 (2020) 109606
The optical properties of the SbSI inverse opals were investigated by reflectance spectroscopy for wavelengths (λ) from 350 to 1000 nm. The reflectance spectra were measured for normal incidence of light on (111) surface of inverse opals. Investigations were performed using the PC2000 (Ocean Optics Inc.) spectrophotometer with a master card equipped with appropriate reflection probe R7x400-2-LOH and the deuterium-halogen light source DH2000-FHS (Ocean Optics Inc.). The samples were mounted in 10 2 Pa vacuum in the optical D2209 chamber of the R2205 cryogenic microminiature refrigeration II-B system based on the Joule–Thomson effect (MMR Technologies Inc.). Using this sys tem and the K77 temperature controller the temperature was regulated in the range 78 K–328 K with an accuracy of 0.1 K. The multiple aver aged spectral characteristics were registered using the OOIBase program from Ocean Optics Inc.
parameter a depends on sphere diameter D and for ideal fcc opals a ¼ pffiffiffi 2⋅D. Sphere diameter was determined on the basis of the SEM images by measurement of average center-to-center distances between spheres and it equals 264(13) nm for sample A, 326(16) nm for sample B and 464 (23) nm for sample C. Fig. 1b presents a part of the photonic band structure calculated in the Γ-L direction using MPB (MIT photonic-bands) software [20,21]. The software calculates photonic band-structures by using a plane wave expansion method. The Γ-L direction corresponds to the normal incidence of light on (111) surface of the fcc structure. The calculation was done assuming that the refractive index estimated for SbSI in opal equals nSbSI ¼ 3.11 [13] and the filling factor of air spheres in SbSI equals fsph ¼ 0.74 (for ideal case - no structural defects were taken into account). The PBGs are marked with grey. They exist between bands 2.-3., 5.-6., and 8.-9. and they are marked by numbers I, II and III, respectively. These gaps appear as maxima on the optical reflectance spectra for λ depending on the lattice constant. Fig. 1c presents reflection spectra R(λ) of samples A, B and C registered at room temperature (RT) and for the range of strongly absorbed light in SbSI crystals that was determined on the basis of [16]. Due to the various sphere diameter, a different part of the photonic band structure is visible in each case. Fig. 2 shows reflectance spectra registered in different temperatures for samples A, B, and C. In every case, the influence of temperature is observed. All peaks are shifted as the temperature changes (Fig. 3). In the case of sample A, the position of peak I moves toward longer wavelengths by 21 nm as the temperature increases from 133 K to 333 K. The peak I for sample B moves only by 6 nm in the investigated range of temperature while the peaks II and III for sample B red shift by about 30 nm. The changes in positions of the same peaks in sample C are different. In the low temperatures, the peaks have blue-shift as the temperature increases up to 140 K and then red shift occurs. The refractive index and lattice constant are parameters affecting the photonic band structure and thus the reflection spectrum. So, the shift of peaks positions is caused by temperature changes of refractive indices and thermal expansion (TE) of SbSI. The refractive index value of crystalline SbSI can be varied by 0.2 for nc and by about 0.1 and 0.01 for nb and na, respectively in the temperature range from 100 K to 300 K [17]. A change in the refractive index by 0.2 should shift the position of the peak I in SbSI inverse opal with 264 nm spheres by about 40 nm. It should be taken into account that SbSI in inverse opal is polycrystalline and the behavior of the effective refractive index with the change of temperature is still unknown. The second effect that should be taken into consider ation is thermal expansion. In the investigated range of temperature, the lattice volume of SbSI can change by about 0.9% [18]. Assuming that the thermal expansion of SbSI in inverse opal affects only its effective refractive index, i.e. increasing of SbSI volume fraction results in the reduction of the air fraction, TE should affect the position of the peak within 10 nm. The strong influence of SbSI electronic band gap on the reflectance spectra is observed. It emerges when the edge of PBG overlaps with the electron absorption band. Since the Eg depends on temperature it is possible to change its position relative to the photonic stop bands. When the electronic and photonic band gaps are close to each other the optical spectra are modified by phenomena associated with slow photons. This is clearly visible in Fig. 2. However, depending on the size of the spheres, this effect is evident for different peaks. In the sample A, the electronic band gap of SbSI affects the peak corresponding to the band I and during cooling causes its deformation forming the shoulder on the shorter wavelength side. Bands II and III are located close to each other so in sample B the Eg probably affects both of them. In the case of sample C, the Eg is located on the left side of the III band and causes a similar effect to observed in sample A. These changes influence on peaks positions, too (Figs. 2 and 3).
3. Results and discussion SbSI inverse opals of different lattice constants (a) were investigated by SEM and optical reflectometry. Fig. 1a presents the SEM micrograph of one of the samples. It shows the typical hexagonal arrangement of pores characteristic for the plane (111) of fcc structure. In opals
Fig. 1. a) Typical SEM micrograph of SbSI inverse opal (sample C); b) photonic band structure of inverse opal calculated in the Γ-L direction; the PBG-s are marked with grey; c) reflection spectra of SbSI inverse opals registered in RT; spectra are vertically displaced for better clarity; the range of strongly absorbed wavelengths are marked with orange. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.) 2
A. Starczewska et al.
Optical Materials 100 (2020) 109606
Fig. 2. Reflection spectra of SbSI inverse opals for different temperatures. Spectra for the highest and lowest temperature are presented in the bottom part of the figures. In the upper part results with an increment of 20 K are presented; spectra are vertically displaced for better clarity; the range of strongly absorbed wave lengths is marked with orange. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)
Fig. 3. The temperature dependencies of peak positions in the reflectance spectra of SbSI inverse crystals (samples A, B, and C).
4. Conclusions
Marian Nowak: Project administration.
For the first time, the influence of temperature and spheres sizes on optical reflectance spectra of SbSI inverse opals were investigated. The peaks associated with photonic band structure are visible. These peaks are shifted as the temperature changes due to changing of refractive index and probably thermal expansion. In addition, the presented changes in the shape of the spectrum near Eg depend on the temperature. These modifications are an expression of the existence of slow photons. For this reason, it should be expected that the SbSI inverse opal structure could have better photovoltaic properties than other forms of this compound. Further investigations of noticed effects should be per formed in detail in the near future.
Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Acknowledgments This paper was partially supported by the Silesian University of Technology (Gliwice, Poland).
Author contribution
References
Anna Starczewska: Conceptualization, Resources, Investiga tion, Writing - Original Draft, Visualization, Writing - Review & Editing. � ska: Investigation, Writing - Original Draft, Mirosława Kępin Visualization, Writing - Review & Editing. Piotr Szperlich: Resources, Writing - Review & Editing. Piotr Duka: Software, Visualization, Writing - Review & Editing.
[1] J.D. Joannnopoulos, S.G. Johnson, J.N. Winn, R.D. Meade, Photonic Crystals: Molding the Flow of Light, Princeton University Press, Princeton, 2008. [2] S. Nishimura, N. Abrams, B.A. Lewis, L.I. Halaoui, T.E. Mallouk, K.D. Benkstein, J. van de Lagemaat, A.J. Frank, J. Am. Chem. Soc. 125 (20) (2003) 6306–6310. [3] L. Liu, J. Jin, Y. Li, H.W. Huang, C. Wang, M. Wu, L.H. Chena, B.L. Su, J. Mater. Chem. 2 (2014) 5051–5059. [4] X. Chen, J. Ye, S. Ouyang, T. Kako, Z. Li, Z. Zou, ACS Nano 5 (6) (2011) 4310–4318.
3
A. Starczewska et al.
Optical Materials 100 (2020) 109606
[5] X. Cui, Y. Wang, G. Jiang, Z. Zhao, C. Xu, Y. Wei, A. Duan, J. Liu, J. Gao, RSC Adv. 4 (30) (2014) 15689–15694. [6] M. Wu, J. Jin, J. Liu, Z. Deng, Y. Li, O. Deparis, B.L. Su, J. Mater. Chem. 1 (48) (2013) 15491–15500. [7] X. Zhang, Y. Liu, S.T. Lee, S. Yang, Z. Kang, Energy Environ. Sci. 7 (4) (2014) 1409–1419. [8] V.M. Fridkin, Photoferroelectrics, Springer-Verlag, New York, 1979. [9] K. Mistewicz, M. Nowak, D. Str� oz_ , Nanomaterials 9 (4) (2019) 580. [10] M. Nowak, A. Nowrot, P. Szperlich, M. Jesionek, M. Kępi� nska, A. Starczewska, K. Mistewicz, D. Str� oz_ , J. Szala, T. Rzycho� n, E. Talik, R. Wrzalik, Sens. Actuators A Phys. 210 (2014) 119–130. [11] J. Ballato, A.A. Ballato, Waves Random Complex Media 15 (2005) 113–118. [12] A.V. Kanaev, Y. Cao, M.A. Fiddy, Opt. Eng. 44 (9) (2005), 095201. [13] M. Kępi� nska, A. Starczewska, P. Duka, M. Nowak, P. Szperlich, Acta Phys. Pol. 5 (126) (2014) 1115–1117.
[14] A. Starczewska, P. Szperlich, M. Nowak, I. Bednarczyk, J. Bodzenta, J. Szala, Acta Phys. Pol. 126 (5) (2014) 1118–1120. [15] A. Starczewska, P. Szperlich, M. Nowak, T. Rzycho� n, I. Bednarczyk, R. Wrzalik, Mater. Lett. 157 (2015) 4–6. [16] M. Nowak, P. Szperlich, A. Kidawa, M. Kępi� nska, P. Gorczycki, B. Kauch, In Solid State Crystals 2002: Crystalline Materials for Optoelectronics, vol. 5136, 2003, pp. 172–177. � [17] A. Audzijonis, R. Sereika, R. Zaltauskas, Phase Transitions 85 (6) (2012) 542–552. [18] K. Łukaszewicz, A. Pietraszko, J. Stępie� n-Damm, A. Kajokas, Pol. J. Chem. 71 (9) (1997) 1345–1349. [19] A. Starczewska, J. Szala, M. Kępi� nska, M. Nowak, K. Mistewicz, M. Soza� nska, Solid State Phenom. 197 (2013) 119–124. [20] S. Johnson, J. Joannopoulos, Opt. Express 8 (3) (2001) 173–190. [21] S. Johnson, J. Joannopoulos, The MIT photonic-bands package. http://ab-initio. mit.edu/mpb/.
4
Contents lists available at ScienceDirect
Optical Materials journal homepage: http://www.elsevier.com/locate/optmat
Influence of temperature on optical spectra of SbSI photonic crystals � ska, Piotr Szperlich, Piotr Duka, Marian Nowak Anna Starczewska *, Mirosława Kępin Institute of Physics – Center for Science and Education, Silesian University of Technology, Krasi� nskiego 8, 40-019, Katowice, Poland
A R T I C L E I N F O
A B S T R A C T
Keywords: Photonic crystals Inverse opal Optical spectroscopy Antimony sulfoiodide
This work is focused on optical investigations of polycrystalline SbSI photonic crystals. SbSI inverse opals of sphere sizes 264 nm, 326 nm, and 464 nm were prepared. The reflectance spectra were measured for normal incidence of light on (111) surface for the light of range 350–1000 nm. The influence of temperature on reflectance spectra was investigated. The peaks associated with photonic band structure were registered. The results were analysed for the effects of temperature, refractive index, thermal expansion, as well as SbSI elec tronic energy gap (Eg) responsible for the existence of specific effects related to slow photons.
1. Introduction
methods of spherical colloids, e.g. by sedimentation in a gravitational field [13–15] or vertical deposition [2–4,19]. It should be emphasized that this is the simplest and the cheapest template production method that does not require expensive equipment. Simultaneously obtained layers have relatively good quality and a large surface. The use of or dered spheres in the size from several hundred nanometers to several micrometers results in a gap for electromagnetic waves in the visible and near-infrared range. Recently, SbSI photonic crystals with an inverse opal structure have been produced [13–15]. It should be emphasized that SbSI has an electronic band gap (Eg) of 1.9–2.0 eV [8] which cor responds to the visible range of light. In this work, the influence of Eg on the optical spectra of SbSI inverse opals with different sphere sizes and for various temperatures is presented.
The development of new technologies creates the possibility of producing various micro- and nanostructures from known materials, which have different properties compared to bulk materials. Photonic crystals (PC) are one of the most interesting optical structures because of their features. PC are characterized by a periodically variable refractive index, which leads to the appearance of interference effects and, as a consequence, photonic band gaps (PBGs) in the photonic band structure [1]. The range of wavelengths for which PBGs are observed depends on the lattice constant of structure. Other interesting effects can also be observed in PC structures. The latest published studies have been focused on slow photon phenomena [2–7]. Slow photons appear on the edges of PBG and increase light absorption when edges of PBG coinci dence the electronic band gap. This property is useful especially in various types of light-induced phenomena, such as photoconductivity or photocatalysis. Antimony sulphoiodide (SbSI) is one of the most intensively studied photoferroelectric semiconductor in recent years [8–18] because of many interesting properties, e.g.: photovoltaic, pyroelectric, piezoelec tric, pyro-optic, electrooptic, and other nonlinear optical effects. Furthermore, SbSI has relatively high refractive index (na ¼ 2,87, nb ¼ 3, 63 and nc ¼ 4,55 for λ ¼ 633 nm depending on crystallographic direction [11]), which makes it useful material for PC. Therefore SbSI has been used for theoretical modeling of 1D photonic crystals [11,12]. In the case of three-dimensional photonic crystals, various structures are pro posed in the literature: Yablonowite, woodpile or inverse opals [1]. The latter found special interest. They can be obtained using self-assembly
2. Experiment The fabrication of SbSI inverse opal structure involves several steps: synthesis of monosized silica (SiO2) spheres, packing the spheres into opal structure based on self-assembly, infiltration of the voids in opal with SbSI and etching the silica spheres. The details of SbSI inverse opals production were presented in Ref. [15]. The process of infiltration consists of keeping a SiO2 matrix in melted SbSI (in temperature 778 K) under low pressure and then cooling with the rate of 5 K/h. Slow cooling ensures obtaining SbSI in the polycrystalline form which was confirmed by XRD and Raman spectroscopy [15]. Using this procedure, three samples (A, B and C) of SbSI inverse opals for different sphere size were made. Morphology of the produced photonic crystals was characterized using the Phenom ProX desk scanning electron microscope (SEM).
* Corresponding author. E-mail address: [email protected] (A. Starczewska). https://doi.org/10.1016/j.optmat.2019.109606 Received 5 August 2019; Received in revised form 4 December 2019; Accepted 5 December 2019 Available online 18 December 2019 0925-3467/© 2019 Elsevier B.V. All rights reserved.
A. Starczewska et al.
Optical Materials 100 (2020) 109606
The optical properties of the SbSI inverse opals were investigated by reflectance spectroscopy for wavelengths (λ) from 350 to 1000 nm. The reflectance spectra were measured for normal incidence of light on (111) surface of inverse opals. Investigations were performed using the PC2000 (Ocean Optics Inc.) spectrophotometer with a master card equipped with appropriate reflection probe R7x400-2-LOH and the deuterium-halogen light source DH2000-FHS (Ocean Optics Inc.). The samples were mounted in 10 2 Pa vacuum in the optical D2209 chamber of the R2205 cryogenic microminiature refrigeration II-B system based on the Joule–Thomson effect (MMR Technologies Inc.). Using this sys tem and the K77 temperature controller the temperature was regulated in the range 78 K–328 K with an accuracy of 0.1 K. The multiple aver aged spectral characteristics were registered using the OOIBase program from Ocean Optics Inc.
parameter a depends on sphere diameter D and for ideal fcc opals a ¼ pffiffiffi 2⋅D. Sphere diameter was determined on the basis of the SEM images by measurement of average center-to-center distances between spheres and it equals 264(13) nm for sample A, 326(16) nm for sample B and 464 (23) nm for sample C. Fig. 1b presents a part of the photonic band structure calculated in the Γ-L direction using MPB (MIT photonic-bands) software [20,21]. The software calculates photonic band-structures by using a plane wave expansion method. The Γ-L direction corresponds to the normal incidence of light on (111) surface of the fcc structure. The calculation was done assuming that the refractive index estimated for SbSI in opal equals nSbSI ¼ 3.11 [13] and the filling factor of air spheres in SbSI equals fsph ¼ 0.74 (for ideal case - no structural defects were taken into account). The PBGs are marked with grey. They exist between bands 2.-3., 5.-6., and 8.-9. and they are marked by numbers I, II and III, respectively. These gaps appear as maxima on the optical reflectance spectra for λ depending on the lattice constant. Fig. 1c presents reflection spectra R(λ) of samples A, B and C registered at room temperature (RT) and for the range of strongly absorbed light in SbSI crystals that was determined on the basis of [16]. Due to the various sphere diameter, a different part of the photonic band structure is visible in each case. Fig. 2 shows reflectance spectra registered in different temperatures for samples A, B, and C. In every case, the influence of temperature is observed. All peaks are shifted as the temperature changes (Fig. 3). In the case of sample A, the position of peak I moves toward longer wavelengths by 21 nm as the temperature increases from 133 K to 333 K. The peak I for sample B moves only by 6 nm in the investigated range of temperature while the peaks II and III for sample B red shift by about 30 nm. The changes in positions of the same peaks in sample C are different. In the low temperatures, the peaks have blue-shift as the temperature increases up to 140 K and then red shift occurs. The refractive index and lattice constant are parameters affecting the photonic band structure and thus the reflection spectrum. So, the shift of peaks positions is caused by temperature changes of refractive indices and thermal expansion (TE) of SbSI. The refractive index value of crystalline SbSI can be varied by 0.2 for nc and by about 0.1 and 0.01 for nb and na, respectively in the temperature range from 100 K to 300 K [17]. A change in the refractive index by 0.2 should shift the position of the peak I in SbSI inverse opal with 264 nm spheres by about 40 nm. It should be taken into account that SbSI in inverse opal is polycrystalline and the behavior of the effective refractive index with the change of temperature is still unknown. The second effect that should be taken into consider ation is thermal expansion. In the investigated range of temperature, the lattice volume of SbSI can change by about 0.9% [18]. Assuming that the thermal expansion of SbSI in inverse opal affects only its effective refractive index, i.e. increasing of SbSI volume fraction results in the reduction of the air fraction, TE should affect the position of the peak within 10 nm. The strong influence of SbSI electronic band gap on the reflectance spectra is observed. It emerges when the edge of PBG overlaps with the electron absorption band. Since the Eg depends on temperature it is possible to change its position relative to the photonic stop bands. When the electronic and photonic band gaps are close to each other the optical spectra are modified by phenomena associated with slow photons. This is clearly visible in Fig. 2. However, depending on the size of the spheres, this effect is evident for different peaks. In the sample A, the electronic band gap of SbSI affects the peak corresponding to the band I and during cooling causes its deformation forming the shoulder on the shorter wavelength side. Bands II and III are located close to each other so in sample B the Eg probably affects both of them. In the case of sample C, the Eg is located on the left side of the III band and causes a similar effect to observed in sample A. These changes influence on peaks positions, too (Figs. 2 and 3).
3. Results and discussion SbSI inverse opals of different lattice constants (a) were investigated by SEM and optical reflectometry. Fig. 1a presents the SEM micrograph of one of the samples. It shows the typical hexagonal arrangement of pores characteristic for the plane (111) of fcc structure. In opals
Fig. 1. a) Typical SEM micrograph of SbSI inverse opal (sample C); b) photonic band structure of inverse opal calculated in the Γ-L direction; the PBG-s are marked with grey; c) reflection spectra of SbSI inverse opals registered in RT; spectra are vertically displaced for better clarity; the range of strongly absorbed wavelengths are marked with orange. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.) 2
A. Starczewska et al.
Optical Materials 100 (2020) 109606
Fig. 2. Reflection spectra of SbSI inverse opals for different temperatures. Spectra for the highest and lowest temperature are presented in the bottom part of the figures. In the upper part results with an increment of 20 K are presented; spectra are vertically displaced for better clarity; the range of strongly absorbed wave lengths is marked with orange. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)
Fig. 3. The temperature dependencies of peak positions in the reflectance spectra of SbSI inverse crystals (samples A, B, and C).
4. Conclusions
Marian Nowak: Project administration.
For the first time, the influence of temperature and spheres sizes on optical reflectance spectra of SbSI inverse opals were investigated. The peaks associated with photonic band structure are visible. These peaks are shifted as the temperature changes due to changing of refractive index and probably thermal expansion. In addition, the presented changes in the shape of the spectrum near Eg depend on the temperature. These modifications are an expression of the existence of slow photons. For this reason, it should be expected that the SbSI inverse opal structure could have better photovoltaic properties than other forms of this compound. Further investigations of noticed effects should be per formed in detail in the near future.
Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Acknowledgments This paper was partially supported by the Silesian University of Technology (Gliwice, Poland).
Author contribution
References
Anna Starczewska: Conceptualization, Resources, Investiga tion, Writing - Original Draft, Visualization, Writing - Review & Editing. � ska: Investigation, Writing - Original Draft, Mirosława Kępin Visualization, Writing - Review & Editing. Piotr Szperlich: Resources, Writing - Review & Editing. Piotr Duka: Software, Visualization, Writing - Review & Editing.
[1] J.D. Joannnopoulos, S.G. Johnson, J.N. Winn, R.D. Meade, Photonic Crystals: Molding the Flow of Light, Princeton University Press, Princeton, 2008. [2] S. Nishimura, N. Abrams, B.A. Lewis, L.I. Halaoui, T.E. Mallouk, K.D. Benkstein, J. van de Lagemaat, A.J. Frank, J. Am. Chem. Soc. 125 (20) (2003) 6306–6310. [3] L. Liu, J. Jin, Y. Li, H.W. Huang, C. Wang, M. Wu, L.H. Chena, B.L. Su, J. Mater. Chem. 2 (2014) 5051–5059. [4] X. Chen, J. Ye, S. Ouyang, T. Kako, Z. Li, Z. Zou, ACS Nano 5 (6) (2011) 4310–4318.
3
A. Starczewska et al.
Optical Materials 100 (2020) 109606
[5] X. Cui, Y. Wang, G. Jiang, Z. Zhao, C. Xu, Y. Wei, A. Duan, J. Liu, J. Gao, RSC Adv. 4 (30) (2014) 15689–15694. [6] M. Wu, J. Jin, J. Liu, Z. Deng, Y. Li, O. Deparis, B.L. Su, J. Mater. Chem. 1 (48) (2013) 15491–15500. [7] X. Zhang, Y. Liu, S.T. Lee, S. Yang, Z. Kang, Energy Environ. Sci. 7 (4) (2014) 1409–1419. [8] V.M. Fridkin, Photoferroelectrics, Springer-Verlag, New York, 1979. [9] K. Mistewicz, M. Nowak, D. Str� oz_ , Nanomaterials 9 (4) (2019) 580. [10] M. Nowak, A. Nowrot, P. Szperlich, M. Jesionek, M. Kępi� nska, A. Starczewska, K. Mistewicz, D. Str� oz_ , J. Szala, T. Rzycho� n, E. Talik, R. Wrzalik, Sens. Actuators A Phys. 210 (2014) 119–130. [11] J. Ballato, A.A. Ballato, Waves Random Complex Media 15 (2005) 113–118. [12] A.V. Kanaev, Y. Cao, M.A. Fiddy, Opt. Eng. 44 (9) (2005), 095201. [13] M. Kępi� nska, A. Starczewska, P. Duka, M. Nowak, P. Szperlich, Acta Phys. Pol. 5 (126) (2014) 1115–1117.
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