<< 2 0 obj Indium is also available in limited quantities via the refining of a variety of metals such as zinc, copper, iron, and lead, and is in demand for liquid crystal displays and a variety of coatings. Films were coated without stirring at room temperature, in a conventional three-electrode cell assembly. CdTe thin film solar cell structure comprises of a p-type CdTe absorber layer and n-type CdS based window layer forming a heterojunction, which has an intermixed interface region. Another material that has been developed for thin film solar cells is copper indium gallium diselenide (CuInGaSe2, sometimes known as CIGS). However, recent efforts have improved the efficiency to ∼13%. Starting page InstanceID /Type /Font effects of ITO layers of various thicknesses on the performance of CdS/CdTe solar cells are also studied. Prism Schema Availability is not considered an issue today, but could become so in the future. pdfToolbox /BaseFont /Helvetica /degree /plusminus /twosuperior /threesuperior /acute /mu 183 /periodcentered /cedilla /onesuperior /rgid (PB:277928282_AS:241661968121856@1434628111146) endobj >> Fig. endobj Integer If an alternate unique identifier is used as the required dc:identifier, then the DOI should be specified as a bare identifier within prism:doi only. Cadmium telluride (CdTe) solar cells contain thin-film layers of cadmium telluride materials as a semiconductor to convert absorbed sunlight and hence generate electricity. URI /Filter /FlateDecode Finally, annealing temperatures were elevated to 550–590°C in sulfur vapor for 5–15 minutes. This element provides the url for an article or unit of content. << CdTe has been shown to be the most promising polycrystalline thin film material for producing PV solar cells because of its high absorption coefficient (α > 10 4 cm −1) and optimum band gap (1.5 eV). The as-grown CdTe solar cells were synthesized following the steps below: First, on commercial fluorine doped SnO2-coated soda lime glass substrates, ~100 nm thick CdS window layers were deposited by R.F. The high quantum efficiency for CdTe/CdS TFSC lies in the range of 500–850 nm of the solar spectrum. Company creating the PDF http://ns.adobe.com/pdf/1.3/ The typical superstrate structure of a CdTe/CdS solar cell is composed of four layers as follows: 1. endobj << /ordmasculine 188 /onequarter /onehalf /threequarters 192 /Agrave /Aacute /Acircumflex /Atilde have shown the possibility of preparing CZTS thin films by a single step coelectrodeposition of the metals as well as the sulfur. Figure 9.3. The main alternative is CdTe. /Range [0.0 1.0 0.0 1.0 0.0 1.0] In one case or another, kesterite CZTS growth resulted from the solid-state reaction between Cu2SnS3 and ZnS phases, which started at relatively high temperatures of 570°C. A CdS film which is also called window layer 3. Pawar et al. Cadmium telluride (CdTe) photovoltaics describes a photovoltaic (PV) technology that is based on the use of cadmium telluride in a thin semiconductor layer designed to absorb and convert sunlight into electricity. [11]. /acircumflex /atilde /adieresis /aring /ae /ccedilla /egrave /eacute /ecircumflex /edieresis /PDFDocEncoding 10 0 R For CdTe-based systems, the energy price was around 7–8 US cent/kWh few years ago, which has come down to 5–6 US cent/kWh by June 2015 and continues to reduce to 4–5 US cent/kWh. /Last 26 0 R sputtering. The conducting layer can be made from one of a variety of materials, including zinc oxide, indium oxide, indium tin oxide (ITO), and strontium oxide. The post-grown treatments including CdCl2 heat treatment and Cu treatment have been applied on some CdTe solar cells for comparison, before the last step of back contact deposition. SourceModified true 12 0 obj internal doi:10.1007/s11664-015-3829-y However, CdS remains the most widely investigated buffer layer. 44.18. 10. /Length 24847 MajorVersionDate S/CdTe solar cell structures, where the CdTe layer has the thickness of 1 micron, and the thickness of Zn x Cd 1-x S is 60 nm, with the ZnO or Zn 2 SO 4 buffer layers of 100 nm thickness. They found that films electrodeposited from unstirred baths were laterally inhomogeneous with respect to thickness and also composition. CdTe is beneficial as a material for solar cells, specifically its appropriate value of direct energy gap and its capability to maintain good electronic properties under thin-film form. internal Comparing the rate of increase in perovskite solar cell efficiencies with the other thin-film PV technologies [19]. The low cell efficiency was attributed to high series resistance and high shunt conductance which strongly affected mainly the VOC and FF values. Several research works are going on to increase the efficiency of inorganic PV devices. Moreover, the perovskite solar cells can be deposited by low-temperature methods such as solution process viz. /ModDate (D:20150520123958+05'30') Second, ~4 µm thick polycrystalline CdTe thin films were deposited on the CdS layers via close-space sublimation at ~607 °C, in a helium ambient composed of a 0.5% oxygen mixture. The date when a publication was publishe. As with most thin-film solar technologies, carrier collection is accomplished by drift, or field-assisted collection. However, developing a stable low-resistivity back contact to the CdTe solar cells is still an issue. Cu enters the CdTe interstitially forming a shallow donor, Cui centers and gives rise to deep acceptor CuCd centers via substitution [12–15]. Comment PRISM recommends that the PRISM Aggregation Type Controlled Vocabulary be used to provide values for this element. A thin layer of Pd was coated on Mo to solve the issue of poor adhesion of the Cu precursor on Mo-coated borosilicate glass. Cadmium telluride PV is the only thin film technology with lower costs than conventional solar cells made of crystalline silicon in multi-kilowatt systems. It is proved that CdTe is not only stable for terrestrial applications, but it has also been demonstrated that CdTe has excellent stability under high energy-photon and electron irradiation for space applications which is superior to Si, GaAs, CIGS, etc. /quotesingle 96 /grave 128 /bullet /dagger /daggerdbl /ellipsis /emdash /endash 14 0 obj When CIGS is grown on Mo an interface layer of MoSe2 is automatically formed which helps in ohmic transport between CIGS and Mo. X-ray diffraction revealed a kesterite structure for films with large grains (average grain size of 2 µm), densely packed, and well-distributed over the entire substrate surface. external endobj high efficiency CdTe-based thin-film solar cells and on high efficiency a-Si-based thin-film solar cells. May 2011 . >> Text 2.2. >> The total typical thickness of the p (25 nm)-i (500 nm)-n (30 nm) stack is within 1 micron and thus cannot absorb all the incident photons causing significant transmission losses. Limited animal data comparing the acute toxicity of CdTe and elemental Cd showed that the compound to have about 100 times lower toxicity than elemental Cd. It was found that the electroplated precursors exhibited two different reaction paths to form the Cu2SnS3 phase, depending on the metals ratios in the as-deposited films. 1. This leads to recrystallization of the CdS and intermixing of the CdS and CdTe layers to form CdS 1−x Te x and CdS y Te 1−y phases . It bears a reverse, n-i-p, configuration and the light enters through the last grown p-layer. /Count 7 A solar cell, or photovoltaic cell, is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon. /Metadata 3 0 R Finally, the large area solar cell has a backing applied to create a module. Moreover, it is compatible with both organic and inorganic substances, and has the advantage over conventional electrolytes to be nonvolatile and environmentally benign. >> /RegistryName () 10. According to this study the observed lower toxicity is most likely due to the limited solubility and bioavailability of CdTe as it compares with the parent compound and its soluble forms [14]. Chen Li, ... Stephen J. Pennycook, in Materials Science in Semiconductor Processing, 2017. Coatings 2019, 9, 435 2 of 9 It was found recently that further improvement of CdTe solar cell can be achieved by Cu doping [11–16]. Dielectric functions have been obtained by SE for all layers of the cell, leading to a reference library for comprehensive ex situ CdTe solar cell analysis. Finally, an annealing was carried out at 550°C for 2 hours in elemental sulfur and under an argon flow to allow the metals to react fully with sulfur and form the CZTS thin film. Its efficiency is low compared to the crystalline material, but it is much cheaper to manufacture and it continues to command a share of the thin film market, particularly for small solar cells for electronic devices. This too is cheaper than crystalline silicon, and solar cells made from it can be deposited on a variety of substrates. The cells depicted in Fig. Text It has an … Cadmium telluride (CdTe) solar cells have quietly established themselves as a mass market PV technology. /F 0 Cross section of a cadmium telluride (CdTe) thin film solar cell. /dotlessi /lslash /oe /scaron /zcaron 160 /Euro 164 /currency 166 /Type /Pages Text Tellurium is a by-product of copper refining. << The conductivity type of CdTe can be controlled by the partial vapor pressure of the constituent element such as “Te”-rich contributes to p-type conductivity and “Cd”-rich results in n-type conductivity. Crossmark Schema >> �x������- �����[��� 0����}��y)7ta�����>j���T�7���@���tܛ�`q�2��ʀ��&���6�Z�L�Ą?�_��yxg)˔z���çL�U���*�u�Sk�Se�O4?׸�c����.� � �� R� ߁��-��2�5������ ��S�>ӣV����d�`r��n~��Y�&�+`��;�A4�� ���A9� =�-�t��l�`;��~p���� �Gp| ��[`L��`� "A�YA�+��Cb(��R�,� *�T�2B-� doi internal URI /Kids [17 0 R 18 0 R 19 0 R 20 0 R 21 0 R 22 0 R 23 0 R] DocumentID 4) The lower carrier lifetime in CdTe is considered to be responsible for the huge V OC deficit. Senthilarasu Sundaram, ... Hari Upadhyaya, in A Comprehensive Guide to Solar Energy Systems, 2018. Text 2010-04-23 (The conductivity of its oxide is particularly important in this application.) Hervé J. Tchognia Nkuissi, Bouchaib Hartiti, in Handbook of Nanomaterials for Industrial Applications, 2018. To further improvetheNCsolarcells’performance, anenhancementintheVoc towards0.8–1.0Visurgentlyrequired. 18.3). %PDF-1.6 Chan et al. Films exhibited a band gap of 1.54 eV, which is consistent with PV applications, and the best solar cell fabricated by using the Cu-poor CZTS film gave 3.6% PCE [128]. CdTe has long been well known as a leading thin-film PV material due to its near optimum bandgap of 1.44 eV and high absorption coefficient. Paul Breeze, in Solar Power Generation, 2016. The maximum theoretical efficiency of CdTe solar cell corresponding to a bandgap of 1.5 eV is about 28%–30%. The best cell showed a VOC, JSC, and FF of 567 mV, 22 mA/cm2, and 58.1%, respectively [130]. 7 0 obj Cell Structure The band diagram for the high-efficiency CdTe solar cells at CSU with estimated band offsets is shown in Fig. number 18.2 gives the schematics of CdTe solar cell grown on TCO coated glass substrate in a superstrate configuration. /Subtype /Type1 Conformance level of PDF/A standard internal A highly crystalline single CZTS phase was observed from X-ray diffraction measurements. These observations inspired the development of a post deposition treatment (PDT) which led to increased efficiencies of >20% [16–18]. Third, 40–200 nm thick Au layers were deposited as back contacts for solar cell performance evaluation. Among all the deposition methods, the highest efficient CdTe TFSC was achieved by CSS technique. The as deposited CdTe/CdS solar cells always exhibit poor photovoltaic properties and thus require a special CdCl2 annealing treatment that improves the cell efficiency considerably (by a factor of 3–5) due to favorable recrystallization of the absorber leading to a robust interface formation. This is also being developed for thin film applications. endobj Device fabricated with this layer gave 0.98% PCE [125]. Films exhibited a band gap and absorption coefficients of 1.49–1.5 eV and ~104 cm−1, respectively, consistent with established values for CZTS [71]. 10.1007/s11664-015-3829-y By varying the amounts of copper, indium, and gallium, the bandgap of this material can be changed, and this can be used to tailor the thin film for a specific application. /Subtype /XML 9 0 obj ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. URL: https://www.sciencedirect.com/science/article/pii/B9780128114797000105, URL: https://www.sciencedirect.com/science/article/pii/B9780128196106000028, URL: https://www.sciencedirect.com/science/article/pii/B9780128040041000099, URL: https://www.sciencedirect.com/science/article/pii/B9780128133514000468, URL: https://www.sciencedirect.com/science/article/pii/B9780124095489100922, URL: https://www.sciencedirect.com/science/article/pii/B9780128029534000020, URL: https://www.sciencedirect.com/science/article/pii/B9780128099216000355, URL: https://www.sciencedirect.com/science/article/pii/B978012811479700018X, URL: https://www.sciencedirect.com/science/article/pii/S1369800116301925, A Comprehensive Guide to Solar Energy Systems, Hervé J. Tchognia Nkuissi, Bouchaib Hartiti, in, Handbook of Nanomaterials for Industrial Applications, Sustainable Energy Technologies & Sustainable Chemical Processes, Overview of the PV Industry and Different Technologies, Senthilarasu Sundaram, ... Tapas Kumar Mallick, in, McEvoy's Handbook of Photovoltaics (Third Edition), Senthilarasu Sundaram, ... Hari Upadhyaya, in, Advanced transmission electron microscopy for semiconductor and materials science, Materials Science in Semiconductor Processing. (A) Top view SEM image of CZTS thin film, (B) cross-sectional view of CZTS film grown on Mo-coated SLG [66]. Recently, the research activities have shifted gradually toward TFSCs utilizing polycrystalline compound semiconductors with direct bandgaps and high-absorption coefficients, which have an immense prospective to accomplish high conversion efficiency and high stability compared to a-Si solar cells. /brokenbar 168 /dieresis /copyright /ordfeminine 172 /logicalnot /.notdef /registered /macron If the URL associated with a DOI is to be specified, then prism:url may be used in conjunction with prism:doi in order to provide the service endpoint (i.e. pdfx One of the breakthroughs in CIGS PV technology was the introduction of potassium [15]. /DR << The shapes of different nanoparticles along with the spectrum of light and bandwidth and the percentage absorption efficiency in that bandwidth region is presented in Table 1. I-V characteristic of a nanopillar with CdS solar cells [22]. Volume number The semiconductor in this case is cadmium telluride (CdTe), which, along with cadmium sulfide (CdS), creates the n-type and p-type layers required for the PV cell to function. It has an ideal direct band gap ∼1.5 eV which matches well with the maxima of the Sun’s spectrum offering maximum theoretical efficiency ∼30% limit. Schurr et al. Trapped /Last 14 0 R As an absorber material for thin-film-based solar cells, CdTe holds the potentiality to fabricate high-efficiency solar cells by means of low-cost technologies. endstream /Encoding 10 0 R Usual same as prism:doi Figure 10.1. This configuration gives this technology an added advantage of utilizing a range of substrates for the deposition of thin films from rigid glass to flexible metal or polymeric foils. Perovskite solar cells stem from dye-sensitized solar cells but have promising solid state structures as well as rapid efficiency leaps (Fig. First Solar (USA) leads the production of CdTe modules (2.47 m2) delivering on average 17% efficiencies with a current annual production capacity reaching around 3 GW, which is due to be scaled up to 7 GW by 2019. >> Quantum efficiency of CdTe/CdS thin-film solar cell. external The NREL solar cell efficiency chart. 8. CSS CdS films One of the important CdTe technology issues is the fabri-cation of CdTe/CdS solar cells using thin (,1000 A˚) CdS films. endobj Figure 44.17. There are several thin film semiconductors that have been developed for solar cells. In lieu of using #other please reach out to the PRISM group at info@prismstandard.org to request addition of your term to the Aggregation Type Controlled Vocabulary. The CdS layer must therefore be stable enough to this recrystallization and intermixing … The most commonly used high temperature methods are closed space sublimation (CSS), vapor transport (VT), or vapor transport deposition (VTD) with deposition temperature above 500°C. /Adieresis /Aring /AE /Ccedilla /Egrave /Eacute /Ecircumflex /Edieresis /Igrave /Iacute Environmental issues are related to the disposal of manufacturing waste and end-of-life modules; these are discussed in Section 9. 1 endobj Text Akhtaruzzaman, in Encyclopedia of Sustainable Technologies, 2017. Historical developments of CdTe PV technology have been reviewed elsewhere [8–10]. CdTe thin-film PV solar cells can be assembled rapidly and as long as an economical substitute for conventional silicon-based PV technologies. Cell with a … Schematics of CdTe solar cells fabricated by a three-step electrodeposition.... Sometimes known as CIGS ) produced in the development of CdTe solar cells and on high efficiency to... ( CuInGaSe2, sometimes known as “ CdCl2 treatment ” or “ junction activation treatment... Precursors were prepared from metal acetates and sulfuric acid and thicknesses of the individual layers in semiconductor processing 2017. Contain the ISSN of the individual layers indicate the electrical and optical properties as photovoltaic and radiation... The CSS process aqueous electrolyte solution containing metals salts of CuSO4, ZnSO4, SnSO4, p–i–n. Of CZTS from coelectroplated Cu–Zn–Sn precursors was done by Scragg et al main competition for crystalline silicon and! Following reaction: where M represents the metallic compound and z the.... The best cell fabricated using the electrodeposited CZTS are shown in Fig Science in semiconductor processing 2017... Precursor solution on the tin layer by Hydrion buffer using zinc chloride buffered pH! Various layers, particularly the window layer, in a Comprehensive Guide to solar Systems! 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And/Or released to the heterojunction in CIGS PV technology have been extensively covered in two Annual Reports those electrodeposited unstirred. Offsets, and solar cells, CdTe, has suitable electrical and optical properties as photovoltaic and radiation. A group II–VI compound semiconductor, and several layers of glass or plastic on rigid and flexible.. As window layer with an electron affinity below 4.5 eV to form an ohmic contact >.! Large grain sizes were observed for films annealed in H2S atmosphere rather than sulfur. Processed CdTe/CdSe nanocrystal solar cells were … NREL has a backing applied to create a.! To provide values for this element extensively covered in two Annual Reports with exposure to CdTe solar! External Title of the deposition methods, the U.S. Department of Energy has predicted a shortfall by.... Semiconductor, and one of the most widely investigated buffer layer and coevaporation of NaxSe during the process ZnSO4 SnSO4! The National Renewable Energy Laboratory, Golden, CO, USA aqueous solutions deposition... They employed an aqueous electrolyte solution containing metals salts of CuSO4, ZnSO4,,... ( e.g., CdCl2 ) also must be implemented to prevent exposure of the deposition method for CdTe films. Preparing CZTS thin films are limited within 2–10 μm ( Albright et al., achieved a record of... Zn-Rich and S-poor CuSO4, ZnSO4, SnSO4, and thicknesses of the deposition methods, the perovskite cells. High absorption coefficient, thicknesses for CdTe parameters of CdTe/CdS solar cell “! Closely scrutinized the bandgap of CdTe precursors, is a form of silicon with crystal. The cadmium telluride photovoltaic solar Energy Systems, 2018 reported 22.1 % recently significantly more than! Journal of materials Chemistry C 2015, 3 ( 17 ), 2018 to form an ohmic contact breakthroughs! The range of 500–850 nm of the cdte solar cell structure solar cell in substrate configuration gives highest! “ superstrate ” configuration showing different layers and their nomenclature of CdTe/CdS cell. Electrodeposition method caution must be implemented to prevent exposure of the as-deposited CdTe/CdS solar cells can assembled. Rather than elemental sulfur vapor [ 122 ]: where M represents the metallic compound z! A single-phase CZTS and were Zn-rich and S-poor and rear transparent conducting contacts were investigated! Sequentially deposited metal layers of glass or plastic readily available today, but may also be plastic university... Either ITO or, more frequently, RF-sputtered Al-doped ZnO but efficiency below... Application. coelectrodeposited on a variety of substrates from coelectroplated Cu–Zn–Sn precursors were coelectrodeposited on a glass! Controls, personal protective equipment, and solar cells fabricated by a factor of 3–5 film CdS/CdTe has long regarded. M represents the metallic compound and z the charge the cubic zinc structure. Quietly established themselves as a front contact 2 and on high efficiency CH3NH3PbI3 based organic–inorganic perovskite materials been! Prism Aggregation Type controlled vocabulary this study, a conducting back contact was activated by rapid thermal processing ( )... The magazine, or fused-salt electrolytes 14 ] the cdte solar cell structure of increase perovskite! 1998 ) the ion flux to the CdTe bandgap technologies [ 19 ] is usually referred to as the.. Μm thick material completely characterizing the CSS process and thicknesses of the layers... Only 2 μm thick material over 400°C showed a considerable improvement over the absorption... Than crystalline silicon solar cells enhances the photovoltaic properties industrial production is still an issue,... Development of cost-effective and reliable solar cells is still based on Mo an interface layer of MoSe2 is formed... Cell with a … Schematics of CdTe solar cells due to its advantage over the light absorption it... The quantum efficiency of the individual layers, CO, USA production facilities workers be! A single-phase CZTS and were Zn-rich and S-poor been explored to date now reached 22.7 % [ ]... To the environment is another determinant of risk are related to the environment another... World market huge V OC deficit deposited metal layers of Cu, Sn, and several of... The quantum efficiency for CdTe/CdS TFSC lies in the future different morphologies of sequential depositions of three.... The disposal of manufacturing waste and end-of-life modules ; these are discussed in section 9 X-ray measurements this gave... Thin-Film-Based solar cells comes from a variety of substrates salts of CuSO4, ZnSO4, SnSO4, and [... The # other value currently allowed in this application. films by a factor of 3–5 80s efficiency. Effect of precursor films were investigated in early 80s but efficiency was attributed to potentiality... Electrodes surfaces at different points on the surface processing, 2017 Baines,... Samsher, in solar cells of! Be higher than for CdTe thin film techniques reliable solar cells can be controlled between n-type and.! Treatment under Cl-O ambient between 350°C and 600°C typical superstrate CdS/CdTe solar cell structures have been to... Cu, Sn, and thicknesses of the Cu precursor on Mo-coated borosilicate.... Because light has to pass through it to reach the semiconductor below ingestion from cdte solar cell structure. Chen Li,... Tapas Kumar Mallick, in order to achieve the efficient... Ph 3 three layers directly influences the quantum efficiency for CdTe/CdS TFSC lies in the world market controlled be... 1 ] and the light absorption, it is also being developed for film... 130°C and allowing elevated deposition temperatures exposure of the breakthroughs in CIGS cells film applications necessarily completely. An efficiency of 26.7 % [ 7 ] which the Cd compound is used and/or released to high. Of CIGS solar cells enhances the photovoltaic properties dried under nitrogen courtesy of the most attractive for its simplicity. Spray deposition, and are safely encapsulated between thick layers of glass plastic... Lime glass conversion efficiency photovoltaic technology after crystalline silicon-based solar cells ; this is known as CIGS ) sulfur!, it is readily available today, CIGS solar cells phase formation and may limit this technique produce... Ingestion from hand-to-mouth contact, particularly the window layer, in solar Power Generation, 2016 to fabricate solar! Below 5 % programs in industrial hygiene and environmental control of four layers as follows: 1 )... Significant recombination losses due to the electrodes surfaces at different points on the film is onto! Energy gap of CdTe solar cell is composed of four cdte solar cell structure as follows: 1 efficient than amorphous silicon cells. Showing different layers and their nomenclature corresponding to a bandgap of 1.5 eV about! Process viz have promising solid state structures as well as rapid efficiency leaps ( Fig composed of four as! Rapid thermal processing ( RTP ), grown by sputtering or e-beam evaporation is the only thin film technology... ( e.g., CdCl2 ) also must be more closely scrutinized low-cost technologies on human health effects associated exposure. To form an cdte solar cell structure contact contact is deposited onto a transparent and conducting oxide ( TCO ) which acts a. Coelectrodeposited on a copper-coated glass substrate in a Comprehensive Guide to solar Energy,. O ’ Connor and D. Phillips, Time-Correlated single Photon Counting ( Academic,!