International Journal of Energetica (IJECA) https://www.ijeca.info ISSN: 2543-3717 Volume 6. Issue 2. 2021 Page 60-64 IJECA-ISSN: 2543-3717. December 2021 Page 60 Organometallic Perovskite Solar Cell Mohammed Lakhdar Ayachi 1* , Atman Benhaoua 1 , Ali Tliba 2 , Belgacem Souyei 3 1Department of Physics, Faculty of Exact Science, University of El Oued, ALGERIA 2Lab. VTRS, Faculty of Exact Science, University of El Oued, ALGERIA 3Department of Chemistry, Faculty of Exact Science, University of El Oued, ALGERIA Email*: ayachi-mohammedlakhdar@univ-eloued.dz Abstract –Halide organometallic perovskite has an important role in the efficiency increase of the solar cell. Thus in this work, we formed the basic nucleus of the organic perovskite, and we studied its morphological properties. The X-ray diffraction result shows that this compound is consistent, homogeneous, and has preferential orientation growth be at (100) plane, which means that the experimental conditions which we worked on were optimal. After adding both tin iodide and methylamine chloride in organic solvents (DMF and DMSO). Deposited this mixture by spray pyrolysis method at Specific temperature 120C°, on the glass substrate, a thin black layer formed; the result of X-ray diffraction on this latter layer showed that it is a spectrum of perovskite compound, which has preferential orientation growth be at (110) plane. Via optical proprieties, it found that has low gap energy of 1.78 eV, and transmittance of 1,6% furthermore it has a high absorption coefficient of 8.104 cm-1, in the visible domain. But it has a relatively high value of Auerbach energy 0.6 eV due to the crystal defects. So this compound could be an active layer in the solar cell. Keywords: Auerbach energy, Optical and morphological properties, X-ray diffraction, Crystal defects. Received: 05/10/2021 – Accepted: 20/12/2021 I. Introduction Hybrid organic perovskite has the same structure as mineral perovskite (ABX3) [1]. But A is organic cations such as methylammonium, formamidinium, or rare-earth elements as Cs. B is ions of heavy metal as (Pb+4, Sn+4) [2,3]. As for the X can be (Cl-Br-I-F) [4]. Hybrid organic perovskite has a wide range of applications in electrical engineering such as gas sensors and light-emitting diode (LEDs) [5], but the most important applications are in solar cells [6]. The solar energy conversion efficiency of perovskite solar cells is over high 25%. The preparation methods of these compounds in the laboratories have a major impact on the energy conversion efficiency of these cells [7]. The major obstacle facing relying on these compounds to convert solar energy is instability [8], this due to several factors including humidity [9] and asymmetry between fundamental compounds. Halide perovskite has several kinds, among them we find (CH3NH3PbI3) which has black color and many applications but contains lead which is hazardous on human and deteriorate rapidly [10, 11]. And there is another kind has formula (CH3NH3PbCl3) also contains lead with white color but doesn't have greater applications because of the big gap of energy 3.1 eV [12], this latter type has good propriety that it doesn't deteriorate quickly because the basic nucleus is methylammonium chloride (CH3NH3Cl). another type of compound less hazardous on humans and has high efficiency conversion of solar energy, is (CH3NH3SnI3) has black color with small gap energy of 1.3 eV but it deteriorates very quickly [13]. There are great researches efforts about the instability of active compounds, without forgetting the simulation studies by several software specialized in the field [14, 15]. https://www.ijeca.info/ mailto:ayachi-mohammedlakhdar@univ-eloued.dz Mohammed lakhdar Ayachi et al IJECA-ISSN: 2543-3717. December 2021 Page 61 The novelty of our work is combining between two properties structure stability and high efficiency conversion of energy, by preparing (CH3NH3SnI2Cl) and depositing on glass layer by using spray pyrolysis technique where we prepared methylammonium chloride (CH3NH3Cl) in our lab and we studied the morphological structure and add tin iodide SnI2 to methylammonium chloride and we study some optical and structural parameters of a new compound. II. Method and experience In the first step, CH3NH3Cl was synthesized by mixing 30 ml of methylamine solution (40% in methanol) and 32.3 ml of hydrochloric acid solution (57% by weight in water) in a flask at 0°C in an ice medium for 2 hours with constant stirring. Then put the solution overnight at 60°C, take the solution, and put in the rotavaporator we got white precipitate. Finally, we wash with diethyl ether two or three times and then let this white precipitate at 70°C until dry. In the second step, we take 0.5g of CH3NH3Cl and 1.2 g of SnI2 were mixed in 15ml DMSO because methylammonium chloride does not easily solute in DMF, then put the mixture at 60°C overnight with constant stirring. Afterward, the small beaker was sealed and kept dark at room temperature to avoid reaction with sunlight. After this work we deposit the second compound over the glass layer by using the spray pyrolysis technique at 120°C, we note a brownish-red precipitate on the substrate, afterward heat treating for this second compound at 180°C, until the brownish-red color turns to black. Finally, we get organic perovskite thin film as shown in Figure 1 [16, 17]. Figure 1. Organic perovskite thin film III. Result and discussion III.1 Structural proprieties Figure 2 Shows the X-ray diffraction spectra of methylaminechloride CH3NH3Cl use PROTO AXRD device estimated wavelength Kα of Cu (0.15405nm) scans angular interval between 10 - 80 degree. The peaks which are appeared in CH3NH3Cl at 2θ: 17.75 °, 27.4°, 29.7°, 35.15°, 42.05° , 56.3° , 58.29° , compatible to crystal levels of (100), (111), (310), (210), (224), (320), (321). Based on previous studies prove the formation of first compound (CH3NH3Cl) has tetragonal form. So, the obtained curve demonstrates that the compound has polycrystalline structure in form tetragonal the sharp peak correspond with plan (100) indicates to best crystallization means that preferential orientation be at (100) plan compared with other plans. Figure 2. X-ray Diffraction spectrum of CH3NH3Cl powder The peaks which are appeared in the second compound as shown in Figure 3 (CH3NH3SnI2Cl) at 2θ: 14.01, 21.964, 31.4, 34.61, 41.3, compatible with crystal levels (110), (014), (112), (200), (224 ). Based on previous studies prove the formation of the second compound (CH3NH3SnI2Cl) has a tetragonal form. Thus, the obtained curve demonstrates that the compound has a polycrystalline structure in tetragonal form, the sharp peak corresponding with a plan (110) indicates to best crystallization means that compared with other plans. The assigned (110) and (220) peaks confirm the perovskite phase. Diffraction peaks have a good corresponding with the previous articles. Both perovskite and methylamine chloride powder have tetragonal forms. For selecting inter-reticular distance dhkl and grid constants a and c, we used the following relations [18, 19]. Mohammed lakhdar Ayachi et al IJECA-ISSN: 2543-3717. December 2021 Page 62 Table 1 summarizes some parameters among them dhkl, 2θ, grid parameters, and Miller indexes. 2 2 2 2 2 2 2 sin( ) 1 1 ( ) hkl hkl d n l h k d a c      (1) Figure 3. X-ray Diffraction spectrum of CH3NH3SnI2Cl thin films Table 1. CH3NH3SnI2Cl and CH3NH3Cl parameters:, dhkl, grid parameters, Miller indexes Compound (hkl) 2θ dhkl(A) a(Å)= b(Å) c(Å) CH3NH3Cl 100 17,75 4,995 9,9901 12,8972 111 27,4 3,2538 6,5076 8,4013 310 29,7 3,00688 6,0137 7,7637 210 35,15 2,5521 5,1042 6,5895 224 42,05 2,1479 4,2958 5,5459 321 58,29 1,5822 3,1645 4,0854 CH3NH3SnI2Cl 110 14,01 6,31899 12,6379 16,3155 014 21,964 4,0453 8,0906 10,4449 112 31,4 2,8478 5,6995 7,73531 200 34,61 2,5907 5,1814 6,6891 224 41,3 2,1851 4,3703 5,6421 III.2. Optical proprieties Figure 4 shows the variation of the transmittance versus of the wavelength of CH3NH3SnI2Cl film. It is shown that the transmittance spectrum of 300-900 nm, Splitted to two intervals : the first interval between 600 and 900 nm, the transmittance of deposited film is in the order of 1,6%, low permeability value is caused by the black color of compound, thickness of layer and some crystal defects. Second interval between 300 and 600 nm, the transmittance of deposited film is in the order of 0.05% is very low permeability value is caused by electronic transition between valence band to conduction band so we used Tauc’s relation in determining direct gap energy[20, 21] : 2 ( ) ( ) g h A h E    (2) Where: A is proportional constant, Eg gap energy, α is absorption coefficient, h is Planck constant and ν is wave frequency. Figure 4. Transmittance versus wavelength Figure 5 shows the variation of Tauc quantity of organometallic perovskite, where noticed slow variation at weak energy, after them, we noticed sharp increasing in this quantity, so the intercept between tangent line and energy axis giving a value of gap energy. Auerbach energy Eu is a very important optical quantity in thin films, so we used the following relation for its determination [22]. 0 ( ) ( ) u h Ln Ln E     (3) Figure 5. Curve shows the variation of (αhν)2 versus photon energy Through the spectrum drawing of the variation of Ln(α) versus hυ as shown in Figure 6, we can find the Auerbach energy using the inverted value of the slop Mohammed lakhdar Ayachi et al IJECA-ISSN: 2543-3717. December 2021 Page 63 tangent line with the curve. Auerbach energy value is relatively great due to crystal defects. Figure 6. Curve shows the variation of ln(α) versus photon energy Figure 7 shows the variation of the absorption coefficient. Where found high value in visible and near infrared ranges within 10-5 cm-1 due to black color of films, but in near ultraviolet range noticed increasing in absorption coefficient due to principle transitions between valance band to the conduction band. Figure 7. Curve presented a variation of absorption coefficient (α) versus wavelength IV. Conclusion Through this work, methylamine chloride powder is obtained, which is considered the basic nucleus of organic perovskite where it has the best crystallization and preferential orientation be at (100) level as shown via XRD spectrum. Meanwhile used this compound for producing perovskite thin film by the spray pyrolysis with moving nozzle deposition device at determining temperature (120C°). XRD spectrum shows the best crystallization and preferential orientation at the (100) level. This film has a low bandgap (1,78 eV) and black color, furthermore has high Auerbuch energy (0.6 eV), and very high absorption coefficient in the visible range that's mean can be an active layer in solar cells. References [1] [A. K. Abass, “Synthesis of CdTiO3 thin films and study the impact of annealing temperature on their optical, morphological and structural properties,” Eurasian J. Anal. Chem., vol. 13, no. 5, 2018. [2] Y. Takahashi, H. Hasegawa, Y. Takahashi, and T. Inabe, “Hall mobility in tin iodide perovskite CH3NH3SnI 3: Evidence for a doped semiconductor,” J. Solid State Chem., vol. 205, 2013, pp. 39–43. [3] X. Li, L. Li, Z. Ma, J. Huang, and F. Ren, “Low-cost synthesis, fluorescent properties, growth mechanism and structure of CH3NH3PbI3 with millimeter grains,” Optik (Stuttg)., vol. 142, 2017, pp. 293–300. [4] S. A. Moyez and S. Roy, “Thermal engineering of lead-free nanostructured CH3NH3SnCl3 perovskite material for thin-film solar cell,” J. Nanoparticle Res., vol. 20, no. 1, 2018, [5] Chengxi Zhang, Lyudmila Turyanska, Haicheng Cao, Lixia Zhao, Michael W. Fay, Robert Temperton, James O'Shea, Neil R. Thomas, Kaiyou Wang, Weiling Luan, Amalia Patanè, “Hybrid light emitting diodes based on stable, high brightness all- inorganic CsPbI3 perovskite nanocrystals and InGaN,” Nanoscale, vol. 11, no. 28, 2019, pp. 13450– 13457. [6] D. Li, J. Shi, Y. Xu, Y. Luo, H. Wu, and Q. Meng, “Inorganic-organic halide perovskites for new photovoltaic technology,” Natl. Sci. Rev., vol. 5, no. 4, 2018, pp. 559–576. [7] Ganesh Alwarappan and Md Raiyan Alam and Walid M. I. Hassan and Mohamed F. Shibl and Sherin Alfalah and Sunil Patil and Reza Nekovei and Amit Verma, “Role of organic cation in modern lead-based perovskites,” Sol. Energy, vol. 189, 2019, pp. 86–93. [8] C. L. Chen et al., “Improved open-circuit voltage and ambient stability of CsPbI2Br perovskite solar cells by incorporating CH3NH3Cl,” Rare Met., vol. 39, no. 2, 2020, pp. 131–138. [9] X. Dong et al., “Improvement of the humidity stability of organic–inorganic perovskite solar cells using ultrathin Al 2 O 3 layers prepared by atomic layer deposition,” J. Mater. Chem. A, vol. 3, no. 10, 2015, pp. 5360–5367. [10] J. Bisquert and E. J. Juarez-Perez, “The causes of degradation of perovskite solar cells.” ACS Publications, 2019. [11] Su-Yong Bae, Su Young Lee, Ji-wan Kim, Ha Nee Umh, Jaeseong Jeong, Seongjun Bae, Jongheop Yi, Younghun Kim & Jinhee Choi, “Hazard potential of Mohammed lakhdar Ayachi et al IJECA-ISSN: 2543-3717. December 2021 Page 64 perovskite solar cell technology for potential implementation of ‘safe-by-design’ approach,” Sci. Rep., vol. 9, no. 1, 2019, pp. 1–9. [12] F. Xu, T. Zhang, G. Li, and Y. Zhao, “Synergetic Effect of Chloride Doping and CH3NH3PbCl3 on CH3NH3PbI3− xClx Perovskite‐Based Solar Cells,” ChemSusChem, vol. 10, no. 11 , 2017, pp. 2365– 2369. [13] H. Yao, F. Zhou, Z. Li, Z. Ci, L. Ding, and Z. Jin, “Strategies for Improving the Stability of Tin-Based Perovskite (ASnX3) Solar Cells,” Adv. Sci., vol. 7, no. 2020, pp.10. [14] Hima Abdelkader, Ahmed Khalil Le Khouimes, Abdallah Rezzoug, Mouslem Ben Yahkem, Abderrahmane Khechekhouche, Imad Kemerchou. Simulation and optimization of CH3NH3PbI3 based inverted planar heterojunction solar cell using SCAPS software, International Journal of Energetica, Vol 4, n°1, 2019. pp. 56-59. [15] Abdelkader Hima, Abderrahmane Khechekhouche, Imad Kemerchou, “Enhancing of CH3NH3SnI3 based solar cell efficiency by ETL engineering”, International Journal of Energetica, vol 5, no 1, 2020. [16] K. Deng, Z. Liu, Y. Xin, and L. Li, “PbI2/CH3NH3Cl Mixed Precursor–Induced Micrometer-Scale Grain Perovskite Film and Room-Temperature Film Encapsulation toward High Efficiency and Stability of Planar Perovskite Solar Cells,” Adv. Mater. Interfaces, vol. 5, no. 15, 2018, pp. 1–8. [17] I. Kemerchou, F. Rogti, B. Benhaoua, N. Lakhdar, A. Hima, O. Benhaoua, A. Khechekhouche, “Processing temperature effect on optical and morphological parameters of organic perovskite CH3NH3PBI3 prepared using spray pyrolysis method,” J. nano-and Electron. Phys., no. 11, 3, 2019, pp. 3011. [18] I. Kemerchou, A. Khechekhouche, A. Timoumi, F. Rogti, A. Hima, A. Sadoun, A. Tliba, M. S. Aida, “Study of the chemical structure of CH3NH3PbI3 peroveskite films deposited on different substrates,” J. Mater. Sci. Mater. Electron., vol. 32, no. 3, 2021, pp. 3303–3312. [19] M. Mahmoudi, A. Benhaoua, B. Benhaoua, L. Segueni, R. Gheriani, and A. Rahal, “Study of structural, optical and electricl properties of fluorine- cobalt co-doped tin dioxide Sno2,” Dig. J. Nanomater. BIOSTRUCTURES, vol. 14, no. 4, 2019, pp. 1079–1086. [20] A. S. Hassanien and A. A. Akl, “Optical characteristics of iron oxide thin films prepared by spray pyrolysis technique at different substrate temperatures,” Appl. Phys. A, vol. 124, no. 11, 2018, pp. 1–16. [21] I. M. El Radaf, T. A. Hameed, G. M. El komy, and T. M. Dahy, “Synthesis, structural, linear and nonlinear optical properties of chromium doped SnO2 thin films,” Ceram. Int., vol. 45, no. 3, 2019, pp. 3072– 3080. [22] F. N. C. Anyaegbunam and C. Augustine, “Study of optical band gap and associated urbach energy tail of chemically deposited metal oxides binary thin films,” Dig. J. Nanomater. Biostructures, vol. 13, 2018, pp. 847–856. I. Introduction II. Method and experience IV. Conclusion References