56 Computational and Experimental Research in Materials and Renewable Energy (CERiMRE) Volume 2, Issue 2, page 56-63 eISSN : 2747-173X Submitted : June 28, 2019 Accepted : September 3, 2019 Online : November 24, 2019 doi : 10.19184/cerimre.v2i2.27366 Optimation of Layers Thickness Design of Perovskite Solar Cell (PSC) Using GPVDM Simulation Dita Puspita 1,a 1 Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Jember, Jalan Kalimantan No. 37 Jember 68121 a ummushafiyyah88@gmail.com Abstract. In this research, perovskite solar cells by configuring ITO/PEDOT:PSS/CH3NH3PbI3/ZnO/Al changed to optimize their performance. Modifications are made by varying the thickness of each layer to increase the ideal thickness with an optimal power conversion efficiency (PCE) value. This research used GPVDM software to study several power conversion efficiency (PCE) parameters of ITO/PEDOT:PSS/CH3NH3PbI3/ZnO/Al solar cells. The results of the study show that the power conversion efficiency (PCE) can be increased by adjusting the thickness of the coating, in this study the ideal thickness with the highest power conversion efficiency 25.75% in 1x10 -8 m of ITO, 1x10 -6 m of PEDOT:PSS, 4x10 -7 m of CH3NH3PbI3, 1x10 -8 m of ZnO and 1x10 -9 m of Al. Keywords: PSC, PCE, GPVDM software, layer thickness modification Introduction Solar energy is a reliable alternative energy source because it is abundant and environmentally friendly. In this perspective, developing solar cells is one of the best approaches to convert solar energy into electrical energy based on the photovoltaic effect. Until now, the advancement of solar cell technology is growing so rapidly. For many years, silicon-based solar cells have been used for industrial purposes with efficiencies reaching 30%, especially crystalline silicon-based solar cells [1]. But behind its advantages are high production costs and are difficult for large industries to use. Another alternative is third-generation solar cells. Third-generation solar cells are capable of producing photo-to-electricity conversion devices with high efficiency and much lower production costs. There are several classifications of technologies included in the third generation of solar cell technology, including dye-sensitive solar cells, quantum dot solar cells (QDs), and perovskite-sensitive solar cells [2]. Of the three types of solar cells included in this third-generation solar cell technology, perovskite-based solar cells appear to have a very good opportunity to contribute to large-scale solar energy production based on high PCE and compatibility with scalable processes. However, there are challenges in the perovskite-based solar cell production process, namely long-term stability [3]. Various efforts have been made to maximize the efficiency of perovskite-based solar cells. In research on solar cells based on CH3NH3PbBr3 with a high photovoltage of 0.96 V and the value of the efficiency is 3.8% [4]. In a study on CH3NH3PbI3 measuring 2-3 nm and giving an efficiency of 6.54% [5]. In different studies achieved an astonishing efficiency of 16.2% [6]. Study on the effect of layer thickness on the power conversion efficiency of CH3NH3PbI3 based planar heterojunction solar cells and the results showed by adjusting layer thickness in our case power conversion efficiency was increased from 9.96 % to 12.9 % [7]. And in a study on the CH3NH3PbI3 thickness effect on device efficiency in planar heterojunction perovskite solar cells showed the optimization of the layer thickness yielded devices with efficiencies of up to 11.3%. The results further demonstrate mailto:ummushafiyyah88@gmail.com 57 Computational and Experimental Research in Materials and Renewable Energy (CERiMRE) Volume 2, Issue 2, page 56-63 eISSN : 2747-173X Submitted : June 28, 2019 Accepted : September 3, 2019 Online : November 24, 2019 doi : 10.19184/cerimre.v2i2.27366 that a delicate balance between light absorption and carrier transport is required in these planar heterojunction devices, with the thickest perovskite films producing only very low power conversion efficiencies [8]. Different parameters can increase the PCE of perovskite-based solar cells, one of which is the effect of layer thickness. This research used GPVDM which is a software simulator for photovoltaic, were investigated the effect of layer thickness on PCE in ITO/PEDOT:PSS/CH3NH3PbI3/ZnO/Al solar cells and obtained the ideal thickness. Theoretical Background General Purpose Photovoltaic Device (GPVDM) is a 1D/2D optoelectronic device model, which can be used to simulate solar cells, LEDs, diodes, FETs, etc. Simulations were carried out using the General Purpose Photovoltaic Device Model (GPVDM). This simulator is based on solving Poisson Equation (1) to obtain voltage , ( ) ( ) (1) where front anode ( ) dan back cathode ( ), is the permittivity of free space, is relative permittivity, is the elementary charge, and is free electron and hole population. Something not less important in solar cells is the offset of band edges of the HOMO and LUMO levels will prove responsible for the improvement of all photovoltaic properties of the organic solar cells. Since a deep HOMO level is desirable for obtaining high open-circuit voltage (VOC) since the maximum value of the VOC is determined by the energy difference between the HOMO (Highest Occupied Molecular Orbital) level of the donor and LUMO (Lowest Unoccupied Molecular Orbital) level of the acceptor. Drift diffusion equation (momentum conservation equation) for electron: (2) for hole: (3) dan define the carrier mobility and define and , where is a difference of LUMO mobility and vacuum level and is a difference of HOMO and LUMO mobility. To describe carrier trapping, d-trapping recombination used SRH recombination model for electron and hole, which assume a steady-state distribution of trapped charge carries in the trap states. * ( )+ ( ) (4) 58 Computational and Experimental Research in Materials and Renewable Energy (CERiMRE) Volume 2, Issue 2, page 56-63 eISSN : 2747-173X Submitted : June 28, 2019 Accepted : September 3, 2019 Online : November 24, 2019 doi : 10.19184/cerimre.v2i2.27366 This form of the SRH equation is therefore not suitable for time-domain simulations, where trapping or recombination via trap states dominate charge dynamics. As the charge carriers can not go out of equilibrium [9]. So, to solve the charge density of each trap state explicitly needed to split space up the energy into energy slice and use SRH equations but don’t assume steady-state so solved the SRH equation explicitly in the time domain. Each trap state gets its rate equation (5) rec is the rate at which free electrons get trapped, ree is the rate at which electrons can escape from the trap back to the free electron population, rhc is the rate at which free holes get trapped and rhe is the rate at which holes escape back to the free hole population. Electron recombination rate (Re) in equation (2) can be calculated by subtracting the total number of electrons that escape all traps into the carrier free electron population from the total number of electrons captured from the free carrier population into all traps. An analogous procedure is carried out to calculate Rh for free holes. More detailed equation resolving and device modeling can be found in more detail in [10, 11, 12-16]. Materials and Methods Figure 1, shows the design of ITO/PEDOT:PSS/CH3NH3PbI3/ZnO/Al solar cells in this research. Table 1 is shown initial parameters that were carefully picked from practical and theoretical references. Figure 1. Desain of ITO/PEDOT:PSS/CH3NH3PbI3/ZnO/Al solar cells in this research Table 1. Simulation Parameters Parameters ITO [7] PEDOT:PSS [12] CH3NH3PbI3 [7] ZnO [13] Layers thickness (m) 1x10 -7 2x10 -7 4x10 -7 2x10 -7 Electron mobility (m 2 /V.s) 6.86x10 -7 0.002 0.002 0.02 Hole mobility (m 2 /V.s) 3.75x10 -2 0.002 0.002 0.018 Relative permittivity Ԑr 3 3 20 2250 Eg (eV) 0 1.6 2.1 3.35 Electron affinity (eV) 4.7 1.6 1.6 4.3 Donor concentration (m -3 ) 5x10 26 5x10 25 5x10 25 5x10 25 Acceptor concentration (m -3 ) 5x10 26 5x10 25 5x10 25 5x10 25 59 Computational and Experimental Research in Materials and Renewable Energy (CERiMRE) Volume 2, Issue 2, page 56-63 eISSN : 2747-173X Submitted : June 28, 2019 Accepted : September 3, 2019 Online : November 24, 2019 doi : 10.19184/cerimre.v2i2.27366 This simulation research is based on the study of the effect of different thicknesses on power conversion energy (PCE). Initial thickness given in Table 1 yields power conversion energy 7.2%, fill factors is 55.12%, open circuit voltage is 0.974 V, and short-circuits density of current is -134 A/m 2 . Results and Discussion Optimation of the thickness of every layer was carried out in this research to obtain the ideal thickness of ITO/PEDOT:PSS/CH3NH3PbI3/ZnO/Al solar cells. Modifications are made one by one on every layer thickness parameter to get the maximum PCE value. Figure 2 is presented the curve of the effect of ITO layers thickness on PCE. Figure 2. Effect of ITO thickness on PCE Figure 2 shows the effect of ITO thickness on PCE. The ITO layer thickness of 1x10 -8 m has a maximum PCE value of 7.46%, with a fill factor of 55.05%, an open circuit voltage of 0.975 V, and a short-circuit density of current of -139.04 A/m 2 . So, ITO layer with a thickness 1x10 -8 m was set and further modified the PEDOT:PSS layer thickness was to obtain the curve in Figure 3. 60 Computational and Experimental Research in Materials and Renewable Energy (CERiMRE) Volume 2, Issue 2, page 56-63 eISSN : 2747-173X Submitted : June 28, 2019 Accepted : September 3, 2019 Online : November 24, 2019 doi : 10.19184/cerimre.v2i2.27366 Figure 3. Effect of PEDOT:PSS thickness to PCE From Figure 3 The Maximum PCE on PEDOT:PSS layer at 1x10 -6 m thickness shows 23.59%, with a fill factor is 76.1%, open circuit voltage is 1 V, and a short-circuit density of current of - 312.8 A/m 2 . PEDOT:PSS layer thickness was set to 1x10 -6 m, then CH3NH3PbI3 layer thickness was modified and obtained curve in Figure 4. Figure 4. Effect of CH3NH3PbI3 thickness on PCE In Figure 4 the maximum PCE is 23.89% in the CH3NH3PbI3 layer thickness of 4x10 -7 m, with fill factor 76.11%, an open circuit voltage of 1.003 V, and short-circuit density of current of -312.9 A/m 2 . 61 Computational and Experimental Research in Materials and Renewable Energy (CERiMRE) Volume 2, Issue 2, page 56-63 eISSN : 2747-173X Submitted : June 28, 2019 Accepted : September 3, 2019 Online : November 24, 2019 doi : 10.19184/cerimre.v2i2.27366 At 4x10 -7 m thickness, the CH3NH3PbI3 was set and modified the ZnO layer thickness to obtained curve in Figure 5. Figure 5. Effect of ZnO thickness on PCE Figure 5 shows the maximum PCE of 25.65% at 1x10 -8 m ZnO layer thickness, where fill factor of 87.74%, an open circuit voltage of 1.004 V and short-circuit density of current of -291 A/m 2 . The last, after fixed the ZnO layer thickness at 1x10 -8 m, the Al layer thickness gets modified to obtain the curve in Figure 6. Figure 6. Effect of Al thickness on PCE 62 Computational and Experimental Research in Materials and Renewable Energy (CERiMRE) Volume 2, Issue 2, page 56-63 eISSN : 2747-173X Submitted : June 28, 2019 Accepted : September 3, 2019 Online : November 24, 2019 doi : 10.19184/cerimre.v2i2.27366 The curve of Figure 6 shows the maximum PCE of 25.75% is obtained in Al layer thickness of 1x10 -9 m. The fill factor is 88%, an open circuit voltage is 1.005 V and the short circuit density of current is -292.1 A/m 2 . From Figures 2 to 6 could be presented the thickness optimation of every layer give effect to PCE value and the ideal layer thickness of ITO/PEDOT:PSS/CH3NH3PbI3/ZnO/Al solar cells design with optimum PCE value: ITO layer thickness of 1x10 -8 m, PEDOT:PSS layer thickness of 1x10 -6 m, CH3NH3PbI3 layer thickness of 4x10 -7 m, ZnO layer thickness of 1x10 -8 m and Al layer thickness of 1x10 -9 m. From the layer thickness optimation, PCE value increased from 0.1% to 25.75%. Conclusions ITO/PEDOT:PSS/CH3NH3PbI3/ZnO/Al power conversion efficiency was analyzed using the GPVDM solar cell software simulation. Results show that a good choice of the layer thickness of different materials used in the solar cell increases considerably the PCE ratio. Simulation results show that an improvement at ITO layer thickness of 1x10 -8 m, PEDOT:PSS layer thickness of 1x10 -6 m, CH3NH3PbI3 layer thickness of 4x10 -7 m, ZnO layer thickness of 1x10 -8 m, and Al layer thickness of 1x10 -9 m. It has 25.75% of PCE value. Further PCE enhancements can be optimized by changing layer structure and materials. References [1] National Renewable Energy Laboratory (NREL), 2018, Best Research-Cell Efficiency Chart, executive summary on https://www.nrel.gov/pv/cellefficiency.html accessed on June 5, 2018. [2] G. Coonibear, 2007, Third Generation Photovoltaics, Materials Today, volume 10 (11), page 42-50. [3] M. Alfaz, Bagawan and G. 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