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In this study, copper indium gallium sulfide (CuIn1-xGaxS2) films was deposited on glass substrates using ultrasonic spray pyrolysis technique (USP). The Ga/(In+ Ga) molar ratio in the precursor solutions has been tailored to obtain the stoichiometric films. Chalcopyrite structure of the films was confirmed by XRD analysis. High absorption coefficient values have been obtained for all samples. It has been observed that the optimum Ga/(In+ Ga) ratio in precursor was 0.5 for the best-performed CuInGaS2 thin films., Int Journal Renewable Energy Res, Comillas Pontif Univ, IEEE, IEEE Power Elect Soc, IEEE Ind Applicat Soc, IBERDROLA, KBSoftware, Asociac Ingenieros ICAI, IEEE Secc Espana, IEEE Spanish Power Elect Ind Elect Joint Chapter, Univ Deusto, iMS, bime, Fraunhofer, INESCTEC, Aalborg Univ, CARTIF, EiC, European Commiss ; Inst Elect Informat ; Commun Engineers Japan, Natl Assoc Spanish ICAI Engineers

In this study, copper indium gallium sulfide (CuIn1-xGaxS2) films was deposited on glass substrates using ultrasonic spray pyrolysis technique (USP). The Ga/(In+ Ga) molar ratio in the precursor solutions has been tailored to obtain the stoichiometric films. Chalcopyrite structure of the films was confirmed by XRD analysis. High absorption coefficient values have been obtained for all samples. It has been observed that the optimum Ga/(In+ Ga) ratio in precursor was 0.5 for the best-performed CuInGaS2 thin films., Int Journal Renewable Energy Res, Comillas Pontif Univ, IEEE, IEEE Power Elect Soc, IEEE Ind Applicat Soc, IBERDROLA, KBSoftware, Asociac Ingenieros ICAI, IEEE Secc Espana, IEEE Spanish Power Elect Ind Elect Joint Chapter, Univ Deusto, iMS, bime, Fraunhofer, INESCTEC, Aalborg Univ, CARTIF, EiC, European Commiss ; Inst Elect Informat ; Commun Engineers Japan, Natl Assoc Spanish ICAI Engineers

In this study, highly (1 1 2) oriented crystalline copper indium disulfide (CuInS2) thin films with high mobility have been deposited via ultrasonic spray pyrolysis. Structural and electrical properties of CuInS2 thin films were examined to utilize them in solar cell applications. Various amounts of precursor solution ranging from 0.25 to 2.02 ml/cm(2) were used to form CuInS2 thin films onto the soda lime glass substrates. Scanning electron microscopy (SEM) analysis revealed that all sprayed films were pin-hole and crack free. Atomic percent ratios of the Cu/In and S/In were very close to the targeted stoichiometric ratios of 1/1 and 2/1, respectively. X-ray diffraction (XRD) studies revealed that all the deposited films were polycrystalline and exhibiting the chalcopyrite structure. Optical band gap energy of the films were calculated as 2.85 eV and decreased to 1.40 eV by increasing the solution loading. Hopping mechanism could be considered as the dominant conduction mechanism in the studied temperature range. Carrier concentrations in CuInS2 films were ranging between 10(15) and 10(17) cm(-3). Mobility and the carrier concentration of the CuInS2 thin films deposited from 1.52 ml/cm(2) solution loading were 40.1 cm(2)/V s and 1.69 x 10(17), respectively. At last but not least, the amount of solution used in this study to form CuInS2 thin films was one of the lowest values reported in the literature. (C) 2013 Elsevier Ltd. All rights reserved., Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TBAG-110T326]; Republic of Turkey Ministry of Science, Industry and TechnologyMinistry of Science, Industry ; Technology - Turkey [01072.STZ.2011-2], This study was supported by The Scientific and Technological Research Council of Turkey under the research Grant TBAG-110T326 and by Republic of Turkey Ministry of Science, Industry and Technology under the research Grant 01072.STZ.2011-2.

Zinc oxide (ZnO) nanowires, sensitized with spray pyrolyzed indium sulfide, were obtained by chemical bath deposition. The XRD analysis indicated dominant evolution of hexagonal ZnO phase. Significant gain in photoelectrochemical current using ZnO nanowires is largely accountable to enhancement of the visible light absorption and the formation of heterostructure. The maximum photoconversion efficiency of 2.77% was calculated for the indium sulfide sensitized ZnO nanowire photoelectrodes. (C) 2015 WILEY-VCH Verlag GmbH ; Co. KGaA, Weinheim, Aselsan A S, Turkiye Sise Cam Fabrikalari A S, Halk Enerji Yatirimlari Uretim Ins Taahhut Tic San A S, Dorutek Teknoloji Ltd Sti, Seiso Enerji Sis Muh San Tic A S, GTC Dis Ticaret Ltd Sti, Air Liquide

With this study for the first time effects of post annealing on morphological, structural, optical and electrical properties of spray pyrolyzed copper-indium-gallium-sulfide (CuInGaS2) thin films have been investigated. Pros-and-cons of conventional (CA) and rapid thermal annealing (RTA) have been discussed to obtain the high quality thin film absorbers for solar cell applications. X-ray diffraction analysis revealed that all of the spray pyrolyzed CuInGaS2 thin films have chalcopyrite structures with a highly (112) preferential orientation. Raman spectra also confirmed this structure. However, metal oxide secondary phases such as copper oxide and gallium oxide were detected when the temperature ramp rate was increased during RTA process. Energy dispersive X-ray measurements revealed that both copper and gallium diffused through the surface after annealing processes. Moreover, copper diffusion became pronounced especially at high annealing temperatures. Optical transmission measurements in the wavelength range between 600 and 1100 nm showed that band gap energy of CuInGaS2 thin films was ranging between 1.36 and 1.51 eV depending on the annealing conditions. Very high mobility values have been observed for both processes. The maximum electrical mobility, 30.9 cm(2)/V s, was observed for the films annealed at 600 degrees C via CA. This is the highest reported value among the CuInGaS2 thin film absorbers deposited by both solution and vacuum based techniques. As a result, post-annealing of spray pyrolyzed CuInGaS2 thin films without usage of highly toxic gases, reported in this study, is very promising and environmentally friendly method to produce solar cell quality absorber layers. (C) 2014 Elsevier B.V. All rights reserved., Republic of Turkey Ministry of Science, Industry and TechnologyMinistry of Science, Industry ; Technology - Turkey [01072.STZ.2011-2], This study was supported by Republic of Turkey Ministry of Science, Industry and Technology under the research Grant 01072.STZ.2011-2.

YÖK Tez No: 316527, CuInS2 thin films are one of the I-III-VI2 chalcopyrite-type mixed crystal semiconductor having direct band gap around 1.5 eV and high absorption coefficient. Hence, it is possible to produce highly efficient thin film solar cells from CuInS2 as the absorber layer. In this thesis, CuInS2 thin films have been deposited using spray pyrolysis system equipped with ultrasonic impact nozzle. With this technology, precursor solution is ultrasonically excited using piezoelectric crystals to generate very fine droplets. This allows deposition of homogenous and defect free films. Here, effects of system parameters, such as solution amount, stoichiometry, substrate temperature, infuse rate and solvent type on the film properties have been investigated. Structural properties of the CulnS2 thin films were examined through X-ray Diffraction, Energy Dispersive X-ray Analysis and X-Ray Photoelectron Spectroscopy. For the optical characterization of CuInS2 films, the transmission measurements have been carried via UV-VIS-NIR spectroscopy. Electrical resistivity and the photosensitivity of the films have been determined from room temperature I-V measurements. Moreover, temperature dependent electrical conductivity have been performed to investigate the carrier concentrations and the mobility CuInS2 films. Structural characterization of CuInS2 films revealed that both increasing the Cu concentration in precursor and the substrate temperature improved the crystallinity of the films. Low infuse rate values and alcoholic solutions allowed to deposit very homogeneous and agglomerate free films. According to optical transmission data all sprayed films showed high absorption coefficient and desired optical band gap values, which is required for high efficiency absorbers., CuInS2 ince filmler I-III-VI2 grubu elementlerinin oluşturduğu 1,5 eV direkt bant aralığına ve yüksek absorbsiyon katsayısına sahip kalkopirit kristal yapıda bir yarıiletkendir. Bu özellikleri sayesinde CuInS2 ince filmler kullanılarak yüksek verimli ince film güneş pilleri elde edilebilir. Sunulan tez kapsamında CuInS2 ince filmler ultrasonik darbe etkili başlıkların kullanıldığı sprey ısıl ergime sistemi ile elde edilmiştir. Bu teknolojide hazırlanan ön çözeltiler piezoelektrik kristaller vasıtasıyla çok küçük damlacıklar şeklinde püskürtülürler. Bu durum homojen ve kusursuz filmlerin elde edilmesine olanak sağlar. Sunulan tez çalışmasında çözelti miktarı, çözelti stokiyometrisi, alt taş sıcaklığı, püskürtme oranı ve çözücü gibi önemli sistem parametreleri ile kontrollü çalışmalar yapılmıştır. CuInS2 filmlerin yapısal özellikleri X-ışını Kırınımı, Enerji Dağılımlı X-Işını Spektroskopisi ve X-ışını Fotoelektron spektroskopisi teknikleri ile yapılmıştır. Optik karakterizasyonlar için geçirgenlik ölçümleri UV-VIS-NIR spektroskopisi ile yapılmıştır. Elektriksel direnç ve fotohassasiyet değerleri oda sıcaklığında yapılan I-V ölçümleri ile belirlenmiştir. Bunlara ek olarak, taşıyıcı yoğunluğu ve mobilite değerlerinin hesaplanması için sıcaklık bağımlı elektriksel iletkenlik ve Hall ölçümleri yapılmıştır. CuInS2 üzerinde yapılan yapısal analizler çözelti içerindeki Cu derişiminin ve alt taş sıcaklığının artışının film kristalinitesini kritik olarak değiştirdiğini göstermiştir. Düşük çözelti akış hızlarının uygulandığı ve alkol esaslı çözücülerden elde edilen filmler daha homojen ve yüzeylerinde aglomerasyonların olmadığı filmlerin elde edilmesine olanak sağlamıştır. Optik geçirgenlik verilerine göre, elde edilen tüm filmlerin, yüksek verimli güneş hücrelerinin üretimi için gerekli olan yüksek soğurma katsayısı ve uygun yasak bölge enerji aralığına sahip olduğu saptanmıştır.

Copper indium disulphide (CuInS2) thin films have a huge potential as absorber layer for thin film photovoltaic applications. In this work, a very simple, and therefore, cost-effective technique, ultrasonic spray pyrolysis, have been used to deposit CuInS2 films on soda lime glass substrates. Two different nozzles, with 48 and 120 kHz frequencies, were used to control the droplet size of the precursor solution. It has been observed that nozzle frequency had a dramatic effect on both solution consumption and the surface morphology of the films. Scanning electron microscopy (SEM) analysis of the films revealed that 48 kHz nozzle resulted very rough surfaces and low adhesion. On the other hand, 120 kHz nozzle resulted lower deposition yield than 48 kHz nozzle due to the smaller droplet size. Energy Dispersive X-Ray Analysis (EDAX) has been used to determine the chemical structure of sprayed CuInS2 films. Films deposited using 20 ml precursor solution and 120 kHz nozzle had the closest Cu:In:S atomic ratio to the targeted 1:1:2 value. Crystal structure of the spray-deposited films was confirmed using X-ray Diffraction (XRD) analysis. Regardless of the solution amount and the nozzle frequency, polycrystalline CuInS2 thin films were observed. All sprayed films showed nanocrystalline nature. As a general trend, optical transmission and band gap energy values of the films decreased with increasing the solution amount for both 48 and 120 kHz nozzles. The absorption coefficient of sprayed CuInS2 films was found to be in the order of 10(5)-10(3) cm(-1) in the wavelength range 200-2000 nm. As a result, in terms of solution consumption 48 kHz nozzle was superior to the 120 kHz nozzle. However, 120 kHz nozzle allows us to obtain more homogenous and well crystallized films., Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TBAG-110T326], This study was supported by The Scientific and Technological Research Council of Turkey under the research Grant TBAG-110T326.

In this study, a simple and cost effective route to tailor the structural, electrical and optical properties of the indium sulfide (In2S3) thin films have been presented. Effects of silver incorporation via in situ doping have been investigated in detail using various characterization tools. XRD patterns confirmed that all of the spray-pyrolyzed films had nanocrystalline nature. Both XRD and Raman analysis confirmed a phase change occurred at the silver concentrations exceeded 10% of the indium concentration in the precursor solution. Raman spectra of the films also revealed that bonding of sulfur with silver atoms became apparent when the silver concentration was exceeded 10%. UV-VIS spectrum showed that increase in silver atomic percent in the films caused decreasing the optical band gap. Moreover, it was observed that silver incorporation enhanced the light sensitization of the In2S3 thin films. The photosensitivity of the films with 20% silver was about 2 x 10(3), which was 10x higher than that of samples with no silver. This indicates the huge potential for using silver incorporated In2S3 thin films as the window layer of thin film solar cells. Furthermore, all of the sprayed films were n-type and showed a room temperature resistivity varying between similar to 10(2) and similar to 10(5) Omega cm. As a result, morphological, structural, optical and electrical characterization of the spray pyrolyzed In2S3 films provided that in situ root of silver incorporation used in this study is a very promising method to tailor the physical properties of the In2S3 for thin film solar cell applications even at very low silver concentrations. (C) 2014 Elsevier B. V. All rights reserved., Republic of Turkey Ministry of Science, Industry and TechnologyMinistry of Science, Industry ; Technology - Turkey [01072.STZ.2011-2], This study was supported by Republic of Turkey Ministry of Science, Industry and Technology under the research Grant 01072.STZ.2011-2.

This chapter focuses on the fundamentals of the spray pyrolysis (SP) technology, the formation of oxide nano powders, nano rods and nanocrystalline thin films, and the performance/manufacturing condition relationships of these materials. Specific application areas such as photovoltaic, energy storage, and sensors will also be given in a subsection of the chapter. Moreover, our approach to building nanocrystalline chalcopyrite semiconductor thin films for photovoltaic applications is given. Chalcopyrite semiconductors are good alternatives to silicon-based photovoltaic devices because of their appropriate band gap energy, high absorption coefficient, and stability. Although selenium-based chalcopyrite materials have very high energy conversion efficiencies in photovoltaics, sulfur-based semiconductors have been quickly replacing them due to the non-toxicity of the sulfur-containing materials. This chapter gives information on the nanocrystalline thin-film deposition of both selenium- and sulfur-based chalcopyrite semiconductors via SP. Applications of these materials in the photovoltaic area are also discussed. Furthermore, our very recent work on the SP of copper-based photovoltaic devices on flexible substrates is summarized. Usage of flexible substrates, polymers, and metal foils, which combine the advantages of being very lightweight with mechanical robustness, is discussed. Therefore, spray-pyrolyzed materials can be used in flexible electronic applications or in the areas where the weight/volume ratio is crucial like unmanned air vehicles.

In this study, copper based thin film solar cells with substrate structure have been built via spray pyrolysis method. Toxic material usage was avoided during the material deposition and the post-treatment steps. Novel device configuration of Mo/CuInS2/In2S3/ZnO/AZO-Ag-AZO was studied as a function of the In2S3 buffer layer thickness. In order to utilize the zinc oxide (ZnO) and aluminum doped zinc oxide (AZO) transparent conductive layers, deposited by physical vapor deposition (PVD), on top of the spray pyrolyzed thin films, the RF power was lowered to 30 W. Although this minimized the unwanted penetration of the highly energetic particles, created during PVD process, sheet resistivity of the AZO films increased enormously. Hence very thin silver layer has been deposited between two AZO films. This resulted the decrease in the sheet resistivity more than 10(6) times. Electrical measurements under illumination revealed that short circuit current density (J(sc)), open circuit voltage (V-oc), fill factor (FF) and efficiency (eta) of the Mo/CuInS2/In2S3/ZnO/AZO-Ag-AZO type solar cells increased with increasing the thickness of the In2S3 layer. The maximum J(sc) of 9.20 mA/cm(2), V-oc of 0.43 V, FF of 0.44 have been observed for the 0.94 mu m-thick In2S3 layer. Extraordinarily thick buffer layer provided better diffusion barrier between the absorber and the TCO layers and also resulted better photosensitivity. These could be the key factors to produce substrate configuration of the spray pyrolyzed thin film solar cells. (C) 2015 Elsevier B.V. All rights reserved., Republic of Turkey Ministry of Science, Industry and TechnologyMinistry of Science, Industry ; Technology - Turkey [01072.STZ.2011-2], This study was supported by Republic of Turkey Ministry of Science, Industry and Technology under the research Grant 01072.STZ.2011-2.

In this study, highly (1 1 2) oriented crystalline copper indium disulfide (CuInS2) thin films with high mobility have been deposited via ultrasonic spray pyrolysis. Structural and electrical properties of CuInS2 thin films were examined to utilize them in solar cell applications. Various amounts of precursor solution ranging from 0.25 to 2.02 ml/cm(2) were used to form CuInS2 thin films onto the soda lime glass substrates. Scanning electron microscopy (SEM) analysis revealed that all sprayed films were pin-hole and crack free. Atomic percent ratios of the Cu/In and S/In were very close to the targeted stoichiometric ratios of 1/1 and 2/1, respectively. X-ray diffraction (XRD) studies revealed that all the deposited films were polycrystalline and exhibiting the chalcopyrite structure. Optical band gap energy of the films were calculated as 2.85 eV and decreased to 1.40 eV by increasing the solution loading. Hopping mechanism could be considered as the dominant conduction mechanism in the studied temperature range. Carrier concentrations in CuInS2 films were ranging between 10(15) and 10(17) cm(-3). Mobility and the carrier concentration of the CuInS2 thin films deposited from 1.52 ml/cm(2) solution loading were 40.1 cm(2)/V s and 1.69 x 10(17), respectively. At last but not least, the amount of solution used in this study to form CuInS2 thin films was one of the lowest values reported in the literature. (C) 2013 Elsevier Ltd. All rights reserved., Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TBAG-110T326]; Republic of Turkey Ministry of Science, Industry and TechnologyMinistry of Science, Industry ; Technology - Turkey [01072.STZ.2011-2], This study was supported by The Scientific and Technological Research Council of Turkey under the research Grant TBAG-110T326 and by Republic of Turkey Ministry of Science, Industry and Technology under the research Grant 01072.STZ.2011-2.

Zinc oxide (ZnO) nanowires, sensitized with spray pyrolyzed indium sulfide, were obtained by chemical bath deposition. The XRD analysis indicated dominant evolution of hexagonal ZnO phase. Significant gain in photoelectrochemical current using ZnO nanowires is largely accountable to enhancement of the visible light absorption and the formation of heterostructure. The maximum photoconversion efficiency of 2.77% was calculated for the indium sulfide sensitized ZnO nanowire photoelectrodes. (C) 2015 WILEY-VCH Verlag GmbH ; Co. KGaA, Weinheim, Aselsan A S, Turkiye Sise Cam Fabrikalari A S, Halk Enerji Yatirimlari Uretim Ins Taahhut Tic San A S, Dorutek Teknoloji Ltd Sti, Seiso Enerji Sis Muh San Tic A S, GTC Dis Ticaret Ltd Sti, Air Liquide

With this study for the first time effects of post annealing on morphological, structural, optical and electrical properties of spray pyrolyzed copper-indium-gallium-sulfide (CuInGaS2) thin films have been investigated. Pros-and-cons of conventional (CA) and rapid thermal annealing (RTA) have been discussed to obtain the high quality thin film absorbers for solar cell applications. X-ray diffraction analysis revealed that all of the spray pyrolyzed CuInGaS2 thin films have chalcopyrite structures with a highly (112) preferential orientation. Raman spectra also confirmed this structure. However, metal oxide secondary phases such as copper oxide and gallium oxide were detected when the temperature ramp rate was increased during RTA process. Energy dispersive X-ray measurements revealed that both copper and gallium diffused through the surface after annealing processes. Moreover, copper diffusion became pronounced especially at high annealing temperatures. Optical transmission measurements in the wavelength range between 600 and 1100 nm showed that band gap energy of CuInGaS2 thin films was ranging between 1.36 and 1.51 eV depending on the annealing conditions. Very high mobility values have been observed for both processes. The maximum electrical mobility, 30.9 cm(2)/V s, was observed for the films annealed at 600 degrees C via CA. This is the highest reported value among the CuInGaS2 thin film absorbers deposited by both solution and vacuum based techniques. As a result, post-annealing of spray pyrolyzed CuInGaS2 thin films without usage of highly toxic gases, reported in this study, is very promising and environmentally friendly method to produce solar cell quality absorber layers. (C) 2014 Elsevier B.V. All rights reserved., Republic of Turkey Ministry of Science, Industry and TechnologyMinistry of Science, Industry ; Technology - Turkey [01072.STZ.2011-2], This study was supported by Republic of Turkey Ministry of Science, Industry and Technology under the research Grant 01072.STZ.2011-2.

In this study, a simple and cost effective route to tailor the structural, electrical and optical properties of the indium sulfide (In2S3) thin films have been presented. Effects of silver incorporation via in situ doping have been investigated in detail using various characterization tools. XRD patterns confirmed that all of the spray-pyrolyzed films had nanocrystalline nature. Both XRD and Raman analysis confirmed a phase change occurred at the silver concentrations exceeded 10% of the indium concentration in the precursor solution. Raman spectra of the films also revealed that bonding of sulfur with silver atoms became apparent when the silver concentration was exceeded 10%. UV-VIS spectrum showed that increase in silver atomic percent in the films caused decreasing the optical band gap. Moreover, it was observed that silver incorporation enhanced the light sensitization of the In2S3 thin films. The photosensitivity of the films with 20% silver was about 2 x 10(3), which was 10x higher than that of samples with no silver. This indicates the huge potential for using silver incorporated In2S3 thin films as the window layer of thin film solar cells. Furthermore, all of the sprayed films were n-type and showed a room temperature resistivity varying between similar to 10(2) and similar to 10(5) Omega cm. As a result, morphological, structural, optical and electrical characterization of the spray pyrolyzed In2S3 films provided that in situ root of silver incorporation used in this study is a very promising method to tailor the physical properties of the In2S3 for thin film solar cell applications even at very low silver concentrations. (C) 2014 Elsevier B. V. All rights reserved., Republic of Turkey Ministry of Science, Industry and TechnologyMinistry of Science, Industry ; Technology - Turkey [01072.STZ.2011-2], This study was supported by Republic of Turkey Ministry of Science, Industry and Technology under the research Grant 01072.STZ.2011-2.

In this study, copper based thin film solar cells with substrate structure have been built via spray pyrolysis method. Toxic material usage was avoided during the material deposition and the post-treatment steps. Novel device configuration of Mo/CuInS2/In2S3/ZnO/AZO-Ag-AZO was studied as a function of the In2S3 buffer layer thickness. In order to utilize the zinc oxide (ZnO) and aluminum doped zinc oxide (AZO) transparent conductive layers, deposited by physical vapor deposition (PVD), on top of the spray pyrolyzed thin films, the RF power was lowered to 30 W. Although this minimized the unwanted penetration of the highly energetic particles, created during PVD process, sheet resistivity of the AZO films increased enormously. Hence very thin silver layer has been deposited between two AZO films. This resulted the decrease in the sheet resistivity more than 10(6) times. Electrical measurements under illumination revealed that short circuit current density (J(sc)), open circuit voltage (V-oc), fill factor (FF) and efficiency (eta) of the Mo/CuInS2/In2S3/ZnO/AZO-Ag-AZO type solar cells increased with increasing the thickness of the In2S3 layer. The maximum J(sc) of 9.20 mA/cm(2), V-oc of 0.43 V, FF of 0.44 have been observed for the 0.94 mu m-thick In2S3 layer. Extraordinarily thick buffer layer provided better diffusion barrier between the absorber and the TCO layers and also resulted better photosensitivity. These could be the key factors to produce substrate configuration of the spray pyrolyzed thin film solar cells. (C) 2015 Elsevier B.V. All rights reserved., Republic of Turkey Ministry of Science, Industry and TechnologyMinistry of Science, Industry ; Technology - Turkey [01072.STZ.2011-2], This study was supported by Republic of Turkey Ministry of Science, Industry and Technology under the research Grant 01072.STZ.2011-2.