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Deliang Wang – One of the best experts on this subject based on the ideXlab platform.
Ultrathin CdTe solar cells with Absorber Layer thinner than 0.2 micronsEuropean Physical Journal-applied Physics, 2018Co-Authors: Min Wang, Xun Li, Deliang WangAbstract:
In this study, ultrathin Cadmium telluride (CdTe) solar cells with Absorber thickness from 50 to 200 nm were fabricated. The short-circuit current (JSC) and open-circuit voltage (VOC) were found to decrease significantly with the thickness of Absorber Layer decreasing. The decrease of the JSC was mainly because of the insufficient light absorption. Even so, the JSC was still found to be 8.2 mA/cm2, which was about 32% of that of a normal CdTe solar cell when the thickness of Absorber Layer was reduced to ∼1% of that of a normal CdS/CdTe solar cell, i.e. 50 nm. The reasons, which caused the decrease of VOC, were also discussed in this study. The dark current–voltage characteristics were analyzed and the contribution of ohmic shunting current to the total leakage current was found to increase with the thickness of CdTe Absorber Layer decreasing. The device characteristics of the ultrathin CdTe solar cells under weak light irradiance and at different temperatures were also investigated. This study provides a guideline for the fabrication of ultrathin CdTe solar cells in the future.
thin film cdte solar cells with an Absorber Layer thickness in micro and sub micrometer scaleApplied Physics Letters, 2011Co-Authors: Jun Yang, Deliang WangAbstract:
CdTe thin film solar cell with an Absorber Layer as thin as 0.5 μm was fabricated. An efficiency of 7.9% was obtained for a 1-μm-thick CdTe solar cell. An increased intensity of deep recombination states in the band gap, which was responsible for the reduced open-circuit voltage and fill factor for ultra-thin solar cells, was induced due to the not-well-developed polycrystalline CdTe microstructure and the CdS/CdTe heterojunction and the presence of Cu in the back contact. The experimental results presented in this study demonstrated that 1-μm-thick Absorber Layer is thick enough to fabricate CdTe solar cell with a decent efficiency.
E. V. Grushko – One of the best experts on this subject based on the ideXlab platform.
optical absorptivity and recombination losses the limitations imposed by the thickness of Absorber Layer in cds cdte solar cellsSolar Energy Materials and Solar Cells, 2013Co-Authors: L. A. Kosyachenko, X Mathew, Ya V Roshko, E. V. GrushkoAbstract:
Abstract Calculations of the integrated absorptive capacity of CdTe Layer taking into account the spectral distributions of the standard AM1.5 solar radiation and the absorption coefficient of the material have been carried out. It is shown that the complete absorption of photons (≥99.9%) in CdTe in the hv > E g range takes place at a Layer thickness d more than 20–30 μm, and the absorptivity is about 93% at d =1 μm. Based on the continuity equation and taking into account the recombination at the front and rear surfaces of the CdTe Layer as well as in the space–charge region, the restrictions imposed on the thickness of the Absorber Layer in CdS/CdTe heterojunction are investigated. It is substantiated a combination of material parameters, for which thickness of the CdTe Absorber is minimized. In all cases, along with the mobilities and lifetimes of charge carriers, the concentration of uncompensated impurities in CdTe, which determines the width of the space–charge region, plays a key role in the generation of photocurrent. The obtained results indicate that, when the CdTe Absorber Layer is too thin, it is impossible to avoid a noticeable decrease of the short-circuit current density as compared with a typical thickness of the CdTe Layer (2–3 μm). The decrease in J sc is more than 20% when the thickness of the CdTe Layer is 0.5 μm compared to ~5% for a thickness of 2–3 μm.
Limitations on Thickness of Absorber Layer in CdS/CdTe Solar CellsActa Physica Polonica A, 2012Co-Authors: T.i. Mykytyuk, V.ya. Roshko, L. A. Kosyachenko, E. V. GrushkoAbstract:
Calculations of the integrated absorptive capacity of CdTe Layer taking into account the spectrum of the AM1.5 solar radiation and the absorption coe cient of CdTe are carried out. The recombination losses at the front and rear surfaces of the CdTe Layer and in the space-charge region are also calculated based on the continuity equation. The restrictions on the thickness of CdTe in CdS/CdTe heterojunction have been ascertained taking into account all types of losses. It is shown that in CdTe, the almost complete absorption of photons (99.9%) in the hν > Eg range is observed at a Layer thickness of more than 20 30 μm, and the absorptive capacity of photons in a CdTe Layer of thickness 1 μm is about 93%. The obtained results indicate that when the CdTe Absorber Layer is very thin, it is impossible to avoid a noticeable decrease of the short circuit current density Jsc as compared with a typical thickness of the Absorber Layer. The loss in Jsc is 19 20% when the thickness is 0.5 μm compared to 5% for a thickness of 2 3 μm.
dependence of efficiency of thin film cds cdte solar cell on parameters of Absorber Layer and barrier structureThin Solid Films, 2009Co-Authors: L. A. Kosyachenko, A I Savchuk, E. V. GrushkoAbstract:
Abstract Dependences of the open-circuit voltage, short-circuit current, fill factor, and efficiency of a CdS/CdTe solar cell on the resistivity and thickness of the p-CdTe Absorber Layer, the noncompensated acceptor concentration N a – N d, and carrier lifetime τ in CdTe, are investigated, and optimization of these parameters in order to improve the solar cell efficiency is performed. It has been shown that the observed low efficiency of CdS/CdTe solar cells is caused by the too short electron lifetime in the range of 10 − 10 –10 − 9 s and too thin (3–5 µm) CdTe Layer currently used for fabrication of CdTe/CdS solar cells. To achieve an efficiency of 28–30%, the resistivity and thickness of the CdTe Absorber Layer, the noncompensated acceptor concentration, and carrier lifetime should be ∼ 0.1 Ω·cm, ≥ 20–30 µm, ≥ 10 16 cm − 3 , and ≥ 10 − 6 s, respectively.
Nowshad Amin – One of the best experts on this subject based on the ideXlab platform.
Effect of deep-level defect density of the Absorber Layer and n/i interface in perovskite solar cells by SCAPS-1DResults in physics, 2020Co-Authors: Shahariar Chowdhury, Nowshad Amin, S. A. Shahahmadi, P. Chelvanathan, Sieh Kiong Tiong, Kuaanan Techato, Narissara Nuthammachot, Tanjia Chowdhury, Montri SukluengAbstract:
Abstract In this paper, Solar Cell Capacitance Simulator-1D (SCAPS-1D) was used to study the Absorber Layer defect density and n/i interface of perovskite solar cells versus various cell thickness values. The planar p-i-n structure was defined as PEDOT:PSS/Perovskite/CdS, and its performance was simulated. Power conversion efficiency >25% can be achieved at 400 nm thickness of Absorber Layer, respectively. The study assumed 0.6 eV Gaussian defect energy level below the perovskite’s conduction band with a characteristic energy of 0.1 eV. These conditions resulted in an identical outcome on the n/i interface. These results show constraints on numerical simulation for correlation between defect mechanism and performance.
Perceiving of Defect Tolerance in Perovskite Absorber Layer for Efficient Perovskite Solar CellIEEE Access, 2020Co-Authors: Samiya Mahjabin, Md. Mahfuzul Haque, K. Sobayel, M. S. Jamal, M. A. Islam, V. Selvanathan, Abdulaziz K. Assaifan, Hamad F. Alharbi, K. Sopian, Nowshad AminAbstract:
Controlling the defect in the perovskite Absorber Layer is a very crucial issue for developing highly efficient and stable perovskite solar cells (PSCs) as it exhibits the existence of unavoidable defects even after the careful fabrication process. In this study, the presence of defects in the perovskite Layer has been evaluated through the analysis of its structural and optical properties. Then the investigations on the impact of defect density on perovskite Absorber Layer and its associated solar cell parameters have been carried out by numerical simulation utilizing SCAPS-1D software. Besides the defect density, the thickness of the Absorber Layer has also been varied to find optimum values of cell parameters. It has been found that when the thickness of Absorber and shallow defect density is increased from 200 nm to 800 nm and 1 × 1013 cm-3 to 1 × 1018 cm-3 respectively, power conversion efficiency (PCE) is varied from 26.7% to 0.90%. However, when the thickness and deep defect density are raised from 200 nm to 800 nm and 1 × 1013 cm-3 to 1 × 1016 cm-3, respectively, the PCE is varied from 19.3% to 6.15%. It is revealed that optimum Absorber thickness is 550 nm and the tolerances of shallow level and deep level defect density are 1 × 1017 cm-3 and 1 × 1015 cm-3, respectively.
Study of molybdenum sulphide as a novel buffer Layer for CZTS solar cells2016 3rd International Conference on Electrical Engineering and Information Communication Technology (ICEEICT), 2016Co-Authors: Samina Alam, M. A. Matin, Nowshad AminAbstract:
The Absorber Layer of CZTS solar cell is a compound semiconductor which has favourable optical and electrical properties. Researchers are highly interest to investigate the CZTS solar cells for its earth abundant, non-toxic and low cost feature. Consequently, the Absorber Layer of CIGS is replaced to CZTS Absorber Layer. In this research work, the potentiality of Molybdenum Sulphide (MoS2) as buffer has been investigated to explore the higher performance of CZTS solar cells. SCAPS 2802 simulator was used to evaluate the performance of CZTS solar cells with prospective MoS2 buffer Layer. The possibility of ultra-thin CZTS solar cells was examined and the higher efficiency of 17.03% (Jsc = 29.42 mA/cm2, Voc = 1.01 V and FF = 0.574) was achieved for 1 μm thickness of Absorber Layer. In addition, the proposed CZTS solar cells had better thermal stability at higher operating temperature also.